Plastic Surgery Volume 6: Hand and Upper Extremity (4th Edition) – Peter C. Neligan

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CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
of an obvious clunk may be a sign of scapholunate ligament
damage without complete disruption of the ligament.
The lunotriquetral interosseous ligament can be assessed
by the Kleinman shear test (Fig. 8.11). The examiner grasps
the patient’s wrist in one hand, specifically applying stabiliz­
ing pressure over the lunate, which is palpable dorsally just
beneath the fourth extensor compartment tendons. With the
other hand, the examiner applies dorsally directed pressure
over the pisiform, which applies a shear force directed across
the lunotriquetral articulation.20 Laxity can be assessed by
further grasping the pisiform and triquetrum “unit” and
moving it both palmarly and dorsally in a “shucking”-type
maneuver. This latter is referred to as the lunotriquetral bal­
lottement test.21 Pain and/or instability may indicate injury or
disruption of the lunotriquetral ligament.
Diagnostic tests
At a minimum, assessment of wrist injuries should include
four radiographs: posteroanterior (PA), oblique, lateral, and
PA ulnar deviation. The ulnar deviation view is particularly
important in detecting scaphoid injuries. The lateral view can
evaluate the relationship between scaphoid and lunate; the
normal scapholunate angle is between 30–60° (Fig. 8.12).
Another helpful view for detecting dynamic instability of the
scapholunate ligament is the clenched fist view. When making
a tight fist, load is placed across the wrist, and the capitate is
driven toward the scapholunate articulation, which will make
scapholunate ligament laxity or rupture more evident. To
increase the accuracy of the diagnosis, both anteroposterior
(AP) and PA stress views should be considered.22
With regard to distal radius fractures, there are a few
key metrics that help guide management, and plain radio­
graphs are generally sufficient to determine these measure­
ments. Changes in radial height (normal = 10–13 mm), radial
inclination (normal = 21–25°), and volar tilt (range 2–20°,
Fig. 8.11  Kleinman shear test.
Triquetrum
Pisiform
Lunate
Fig. 8.12  The normal angle between the mid-axis of the scaphoid to the lunate
ranges from 30–60° (average 47°).
average = 11°) help define the extent of fracture displacement
(Fig. 8.13).23
Cross-sectional imaging modalities, such as computed
tomography (CT) and magnetic resonance imaging (MRI), are
also used routinely to investigate wrist injuries. CT is an
X-ray-based modality, and as such it is best for assessing
complex fracture-dislocation patterns. In particular, CT can
help assess joint congruity and/or depressed articular frag­
ments. CT is also better than MRI at determining osseous
healing across a fracture site. On the other hand, MRI is the
preferred modality for assessing nonosseous structures, and
has the added benefit of providing some information about
vascularity of parts of the carpus. MRI technology continues
to evolve, and modern machines can detect very small liga­
mentous injuries. When the modalities of MRI and arthrogra­
phy are combined, even small perforations in the interosseous
ligaments can be detected.
Clinical tip
CT scans are better at showing fracture details and bony
bridging/healing. MRIs are better at showing soft tissue injury,
occult (non-displaced) fractures, and bony edema.
The use of bone scans has decreased substantially over the
years because of the effectiveness of MRIs. Nevertheless, bone
scans are still helpful in identifying “hot areas” of the wrist
in difficult cases when the etiology of the patient’s wrist pain

177
Patient selection
Operative fixation of non-displaced scaphoid fractures has
been debated. Advocates cite many advantages, including
earlier return to active military duty and increased quality-
adjusted life-years.26,27 Despite some evidence of improved
functional outcomes and less time off work, surgical treat­
ment does present some risk of complications and should not
be considered lightly, since the majority of these fractures will
heal nicely with immobilization alone.28,29
Acute scapholunate ligament injuries require operative
repair to maintain carpal alignment and avoid collapse which
can lead to predictable patterns of wrist arthritis.30 However,
unlike bone fixation, which reliably leads to union in most
cases, techniques for repair of interosseous ligaments are not
as predictable. Furthermore, the healing capacity of intercar­
pal ligaments seems to deteriorate over time, so patients
presenting more than 6 weeks after injury may not have any
suitable ligament remnants to attempt an operative repair.
is uncertain. However, the nonspecific nature of the bone scan
limits its usefulness in the evaluation of most injuries.
Diagnostic wrist arthroscopy, while more invasive than the
tests mentioned above, must still be considered the “gold
standard” for detecting intra-articular wrist injuries. In a
recent systematic review comparing MRI results with findings
at arthroscopy, the negative predictive value of MRI for
scapholunate injury ranged from 72–94%.24 In other words,
MRI can never completely rule out ligamentous injury in the
wrist.
One pitfall associated with the increasingly widespread use
of MRI is the inevitable detection of “false positive” findings
in the wrist. It is not uncommon to find multiple minor
abnormalities on high-resolution wrist MRI, many of which
have nothing to do with the patient’s complaints. Therefore,
it is important for the treating physician to use MRI wisely, in
cases where there is reasonable suspicion of injury or occult
pathology, rather than use it indiscriminately.
Patient selection
Indications for fixation of scaphoid fractures are fairly well
established. Because displaced scaphoid fractures cannot be
reduced in a closed fashion, open reduction and internal fixa­
tion (ORIF) is required to restore anatomic alignment. This is
important to facilitate healing in the scaphoid, due to its
tenuous blood supply, and to restore normal scaphoid shape
and alignment, which is important for carpal kinematics.25
Other relative indications are listed in Table 8.2.
Fig. 8.13  (A) Radial height measured as the distance between two lines, the first line perpendicular to the longitudinal axis of the radius and intersecting the distal surface
of the ulnar head, and the second line that passes through the distal tip of the radial styloid. (B) Radial inclination represented by the angle between the line perpendicular
to the longitudinal axis of the radius and a second line connecting the ulnar aspect of the distal radius and the tip of the radial styloid. (C) Volar tilt is the angle between the
line perpendicular to the longitudinal axis of the radius and a line along the distal articular surface of the radius.
A
B
C
Table 8.2  Relative indications for scaphoid fracture fixation
Displaced fractures
Proximal pole fractures (regardless of displacement)
Fractures associated with perilunate injuries
Open fractures
Fractures in multiply injured patients
Fractures not healing after a trial of immobilization (3–4 months)

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CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
pole fractures; waist fractures can be repaired through a volar
or dorsal approach. Although minimally invasive (percutane­
ous) techniques have been developed for scaphoid fractures,
these are not for the novice hand surgeon.
The dorsal approach for ORIF of a scaphoid fracture (Fig.
8.14A) begins with a longitudinal incision just distal and ulnar
to the Lister tubercle, extending over the dorsal wrist (Fig.
8.14B). The third compartment is identified through this inci­
sion, and EPL is partially released, without completely opening
the compartment. With EPL protected, the wrist capsule is
opened longitudinally to expose the scaphoid, identify the
fracture, and examine the nearby scapholunate ligament. The
fracture is then reduced; this can be aided by bone reduction
forceps, or another similar instrument.37 The wrist is then
flexed to fully expose the proximal pole, and the guidewire for
the cannulated headless compression screw is placed down
the long axis of the bone. Ideally, a second wire should be
added to prevent displacement of the fracture during drilling
and screw placement (Fig. 8.14C). This stabilizing wire should
be placed across the fracture into the trapezium for maximum
stability, but it must not interfere with screw placement. Mul­
tiplanar mini C-arm fluoroscopy is used to confirm that the
guidewire is through the central axis of the scaphoid and that
the fracture is reduced. Most screw sets utilize a measuring
tool at this point to select a screw length, based on the length
of guidewire that is protruding from the bone.
The evidence favoring acute repair of lunotriquetral
tears is less convincing. Many authors believe a trial of non­
operative treatment with immobilization is indicated prior to
considering operative repair.21,31
The American Academy of Orthopaedic Surgeons has
published guidelines regarding treatment of distal radius
fractures.32 Non-displaced distal radius fractures typically
heal with immobilization alone and do not require surgical
intervention. Displaced distal radius fractures should undergo
a reduction maneuver before deciding if surgery is needed.
Stable fractures that remain reduced will not require an opera­
tion, but should be followed weekly for 2–3 weeks to be sure
the fracture does not collapse or re-displace. Although the
available evidence does not lend itself to many definitive
recommendations, there is moderate evidence to support
operative fixation of fractures with post-reduction radial
shortening >3 mm, dorsal tilt >10°, and/or intra-articular
displacement or step-off >2 mm.32
Despite the existence of these guidelines, patient selection
does not depend on X-ray findings alone. A patient’s overall
health, comorbidities, pre-injury activity level, job require­
ments, and expectations all play a role in the decision
for surgery. This concept is exemplified in the ongoing inves­
tigation of the optimal treatment of distal radius fractures in
the elderly.
With the development of volar fixed-angle plates with
locking screws, fixation of distal radius fractures quickly
became easier and more predictable, especially for fragility
fractures in older adults.33,34 This has led to an increase in the
operative management of these fractures in the elderly, increas­
ing from 3% in 1996 to 16% in 2005.9 Without surgery, these
fractures predictably result in malunion, with the majority
having less-than-excellent radiographic results.35 However,
patient-reported outcome studies have shown that older adults
tolerate greater degrees of malalignment without difficulty.36
Therefore, an independent, active retiree might do better with
surgical fixation, whereas a low-demand, infirm patient of the
same age might do better with nonoperative treatment.
Treatment and surgical techniques
Scaphoid fractures
The scaphoid appears to be in the shape of a cashew nut, and
can be divided into three segments: distal pole (tubercle),
waist, and proximal pole. Due to the distally-located blood
supply, fractures of the distal pole or tubercle heal reliably
with 6–8 weeks of immobilization, and rarely need surgical
fixation unless significantly displaced. However, as the loca­
tion of the fracture line moves more proximally, the incidence
of nonunion increases, and any measurable displacement
increases this risk. Even non-displaced proximal pole fractures
will take considerable time to heal if treated nonoperatively;
cast treatment can last as long as 6–9 months before healing
is confirmed.
Internal fixation of scaphoid fractures is most commonly
accomplished with a headless compression screw. Placement
of the screw can be challenging, as complete visualization of
the scaphoid is difficult, and the screw should be placed down
the long axis of the bone for best bony purchase with least
risk of extrusion. We advocate a dorsal approach for proximal
A cannulated drill or reamer is then used to gently drill the
hole by hand, frequently checking progress using fluoroscopy.
Consider advancing the guidewire into the trapezium to sta­
bilize it further before drilling. It is important to maintain a
straight trajectory with the drill and avoid bending the guide­
wire, so as to avoid damaging or breaking the wire. The
cannulated screw is then placed on the guidewire and
advanced across the fracture line (Fig. 8.14D). The K-wires are
then removed, final position of the screw is verified with fluo­
roscopy, and the incision closed (Fig. 8.14E).
Scaphoid nonunion
Scaphoid nonunion is not an uncommon occurrence, both
because scaphoid fractures can be missed upon initial exami­
nation, and because the scaphoid’s precarious blood supply
puts it at risk. Many of those who suffer from a scaphoid
nonunion are active young adults who are involved in athletic
activities, and their fracture was either misdiagnosed as a
sprain, or not diagnosed at all. The natural history of scaphoid
nonunion is not precisely known. It is clear that there is an
increased risk of post-traumatic arthritis – the scaphoid non­
union advanced collapse (SNAC) wrist – due to the disruption
of the proximal row biomechanics. What is not known is the
incidence of symptoms, since many asymptomatic patients
Clinical tip
When basing the scaphoid screw measurement on the
guidewire, one must take into account the position of the wire
relative to the distal cortex. If the wire abuts the distal cortex,
at least 2 mm should be subtracted from the given
measurement to ensure the screw does not penetrate into the
scaphotrapezial joint. Generally, screw measurements are
around 22–24 mm for men and 18–20 mm for women.

179
Treatment and surgical techniques
Fig. 8.14  (A) Scaphoid fracture to be treated with
ORIF using a screw. (B) The incision is made ulnar
to the Lister tubercle. (C) Two K-wires are passed
into the scaphoid, one of which is the guidewire for
the cannulated screw. (D) Finally, a compression
screw is inserted into the bone. (E) Final fracture
reduction showing the screw placement.
B
A
C
D
E
never present for treatment of their nonunion.38 Asymptom­
atic patients do not need surgical intervention, but should
probably be followed periodically to monitor for the develop­
ment of symptoms and/or radiographic signs of arthritis.
Patients with symptomatic scaphoid nonunion may be
candidates for operative treatment.39 Advanced imaging is
indicated to determine the exact deformity present in the
scaphoid, and may also provide clues as to the vascularity of
the proximal fragment. Correction of a “humpback” deformity
(see Fig. 8.9) is easiest from the volar approach, as it requires
the fracture site to be opened and a structural graft from either
the iliac crest or from the distal radius inserted to restore the
height of the scaphoid. This approach can also be used to treat
established malunion of the scaphoid with similar deformity.
If there is concern for avascular necrosis, vascularized bone
grafting should be considered to increase the blood flow
to the scaphoid. Typically, this situation arises in proximal
pole fractures, and dorsal approach is preferred. Pedicled
grafts from the dorsal distal radius, such as those based on
the 1,2-intercompartmental supraretinacular artery, reach the
scaphoid easily.40 Although more technically demanding, a
free vascularized bone graft from the medial femoral condyle
is another option (Fig. 8.15).41
Scapholunate ligament injury
Scapholunate ligament injury is the most common form of
carpal instability. It is critical to establish the chronicity of the
injury before developing a treatment plan.
Acute scapholunate injuries present with localized pain
and swelling, but rarely have dramatic findings on radio­
graphs. The diastasis between scaphoid and lunate and the
DISI deformity that characterize this injury often develop
over time as secondary supporting structures attenuate and
degenerate (Fig. 8.16). If radiographs are normal, identifica­
tion of these injuries demands a high degree of clinical suspi­
cion, and may require confirmation with MRI arthrography
or arthroscopy.
Acute partial tears will not have any gross instability and
should heal with 4–6 weeks of immobilization alone. Acute

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CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
Fig. 8.15  (A) The medial femoral condyle flap is taken from the leg and (B,C) grafted into the wrist.
A
B
C
Fig. 8.16  A widened interval between scaphoid and lunate as a result of a
scapholunate ligament tear.
complete tears should be treated with open repair of the liga­
ment using suture anchors or other suitable method. The
repair should be protected with scapholunate and scapho­
capitate (midcarpal) pinning for 8 weeks to allow the ligament
to heal. Many surgeons reinforce such acute repairs with
additional capsulodesis, especially in subacute repairs.42
Repairs delayed greater than several weeks may be difficult,
as the ligament remnants tend to deteriorate over time.30
For patients with chronic tears, the treatment becomes
more complex. Patients with a reducible scapholunate diasta­
sis without arthritic changes may benefit from reconstruction.
Arthroscopy is often utilized to determine the status of the
cartilaginous surfaces and the reducibility of the carpals, but
sometimes a final decision can only be made after open
exploration of the joint. It is important to discuss all potential
options with the patient prior to surgery.
Reconstruction of chronic scapholunate dissociation can
take many forms. For an easily reducible diastasis with some
ligament remnants present, repair with capsulodesis can be
performed, much like in a more acute injury. Our preference
is to perform a dorsal capsulodesis by inserting a mini-bone
anchor into the distal pole of the scaphoid (Fig. 8.17) to anchor
this part of the scaphoid to the dorsal wrist capsule, thereby
preventing volar flexion of the scaphoid and subsequent
impingement on the radial styloid.
Clinical tip
A good indicator of the “reducibility” of chronic scapholunate
dissociation is the ease with which the diastasis can be
corrected using K-wire “joysticks” in the bones to manipulate
them. If the scapholunate articulation can be reduced without
permanently deforming 0.062-inch K-wire joysticks, then
reconstruction can be considered.
If the ligament is not repairable, there have been many
strategies developed to restore the scapholunate linkage,
usually relying on tendon grafts to perform some variety of
tenodesis between the unstable bones. Our preferred tech­
nique uses a slip of the flexor carpi radialis (FCR) tendon
passed through a drill hole in the scaphoid, woven through the

181
Treatment and surgical techniques
Perilunate dislocation
Perilunate injuries are usually diagnosed immediately, as
these patients present with a major wrist injury and often
have acute median neuropathy (Fig. 8.20A). Reduction should
be performed immediately to alleviate this pressure on the
nerve and restore carpal alignment. This maneuver typically
requires sedation, analgesia, and distraction. With careful
manipulation of the wrist into extension, while applying trac­
tion, the capitate can be re-located onto the lunate in most
cases. If the lunate is completely dislocated into the carpal
tunnel, gentle volar pressure should be used to relocate it back
into its place between capitate and radius. Patients presenting
in a delayed fashion will be more difficult to reduce. If reduc­
tion is not possible, consideration should be given to a more
urgent operative intervention, especially in patients with
ongoing nerve impingement.
For definitive repair, we believe both dorsal and volar
approaches are required.13 Volarly, an extended carpal tunnel
incision is performed, crossing the wrist crease (Fig. 8.20B).
After reducing the lunate, the volar capsule tear is closed
using permanent sutures. This repair often incorporates
closure of the space of Poirier as well as repair of the volar
lunotriquetral ligament, if sutures are placed deep enough.
Proponents of a dorsal-only approach to this injury argue
that these ligaments are nicely opposed after reduction, and
sutures are unnecessary.14 However, given the need for carpal
tunnel decompression in the vast majority of these patients,
we perform the capsular repair through this incision as well.
A dorsal wrist exposure (Fig. 8.20C) is then used to confirm
accurate carpal alignment, pin the reduced carpus, and repair
the dorsal scapholunate ligament, typically with suture
anchors. A capsulodesis can be added to reinforce the repair.
The pins are cut below the surface of the skin, to remain in
place for 8 weeks (Fig. 8.20D). We prefer burying the pins to
reduce the risk of postoperative pin track infection. Interest­
ingly, although the lunate is often stripped of all its attach­
ments in this type of injury, avascular necrosis of the lunate
is rare in these patients.
dorsal radiocarpal ligament, and secured to the lunate, which
has been referred to as a three-ligament tenodesis (Fig. 8.18).43
If uncorrected, scapholunate dissociation can lead to wrist
arthritis. Depending on the stage of arthritis at presentation,
various salvage procedures may be indicated. These are
addressed more fully in Chapter 20 of this textbook.
Lunotriquetral ligament injury
Lunotriquetral ligament injuries are more subtle than scaph­
olunate ligament tears. A true lunotriquetral diastasis is rarely
seen on radiographs, although a mild VISI deformity or minor
disruption in the first Gilula arc may help identify the injury
(Fig. 8.19). Because of this subtlety, these injuries are rarely
diagnosed acutely.
If no collapse (VISI deformity) is present, both acute and
chronic injuries can be treated initially with immobilization
and other conservative measures. Operative intervention is
reserved for those wrists that progress to VISI deformity, or
otherwise fail nonoperative management. Surgical treatment
options include ligament repair, ligament reconstruction,
arthrodesis, and ulnar-shortening osteotomy.
Lunotriquetral ligament repair is technically challenging,
typically requiring both dorsal and volar approaches. The
ligament tends to be short and is not amenable to repair in
chronic injuries. Reconstruction with a slip of the extensor
carpi ulnaris tendon passed through drill holes in these bones
has been used with some success to recreate the lunotriquetral
linkage, and is superior to repair in chronic cases.31,44 Ulnar
shortening osteotomy can be useful in unloading a painful
ulnocarpal joint, as in cases of ulnocarpal abutment leading
to lunotriquetral injury, and may help to re-tension secondary
stabilizers in these cases.45
Clinical tip
In perilunate dislocations, it is important to make sure the
carpus is “rebuilt” with the lunate in neutral position (no DISI
or VISI). We begin by placing a temporary pin across the
radiolunate joint, with the lunate in neutral position, verified
with lateral fluoroscopy. The scaphoid and triquetrum are then
reduced to the lunate, and pinned in the appropriate reduced
position. After repairing the dorsal ligaments, the radiolunate
pin is removed.
Distal radius fractures
Most distal radius fractures present as closed injuries; those
that fail conservative treatment can be electively fixed on an
outpatient basis, preferably within 1 week. If fixed within this
time frame, we find that most fragments are easily reducible,
and the deposition of healing callus that can obscure an
accurate reduction is minimized. However, there are a couple
of situations where more urgent intervention might be needed.
Open fractures of the distal radius are a surgical emergency,
especially if there is gross contamination of the fracture site.
Fig. 8.17  A mini-bone anchor used to anchor the distal pole of the scaphoid to
prevent its flexion, which can cause arthritis change at the radial styloid.

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CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
A
B
C
Fig. 8.18  (A) PA X-ray showing mild
scapholunate diastasis and cortical ring
sign. (B) Intraoperative view of chronic
scapholunate dissociation. L, Lunate; S,
scaphoid. (C) Three-ligament tenodesis.
DRC, dorsal radiocarpal ligament;
FCR, flexor carpi radialis tendon.
(D) Postoperative X-ray showing properly
extended scaphoid, bone anchors, and
protective K-wires.
D

183
Treatment and surgical techniques
to the difficulty of protecting these soft tissues from the
hardware in this location.
The modern volar approach is intended to overcome the
problems of dorsal plating. The advantage of the volar plating
technique is the ability to place the plate under the pronator
quadratus muscle, which can shield the plate from injuring
the overlying tendons and nerves. In addition, the introduc­
tion of locking screws made rigid fixation from the volar side
possible irrespective of the amount of comminution of the
dorsal metaphysis (Fig. 8.21). Traditional non-locking screws
must adequately engage both cortices in order to secure the
plate to bone using friction. While locking screws do engage
the bone to some extent, they also have threads on the screw
head to engage the plate itself. This prevents the screw from
“toggling” due to pressure across the fixed fracture. Further­
more, each screw can be firmly positioned in space to lend
three-dimensional support beneath the articular surface of the
radius. This construct is rigid enough in most cases to allow
for early gentle motion of the wrist in routine cases.
Volar plating does have several nuances that one must pay
attention to during exposure to prevent unnecessary compli­
cations.46 First, the volar incision must be made radial to the
FCR tendon to protect the palmar cutaneous branch of the
median nerve, which is found immediately ulnar to the FCR
at the wrist. Next, instead of incising the pronator quadratus
down the middle, the muscle should be elevated as an ulnarly
based flap by dividing its insertion on the radius. This makes
coverage of the plate easier at the conclusion of the case. For
the distal locking screws, the lengths should be measured
very carefully. We advocate using screws 1–2 mm shorter than
the depth gauge measurement to prevent screw-tip related
injuries to the extensor tendons. Finally, once the plate has
been completely installed, fluoroscopy should be performed
in multiple planes to ensure correct implant and screw posi­
tion. Specifically, an offset lateral view should be used to
examine the radiocarpal joint. By angling the wrist about 30°
(equal to the radial inclination of the joint), one can get a view
down the articular surface to make sure no distal screws
penetrate the joint (Fig. 8.22). Adhering to these guidelines
will allow for effective plating, with minimal complications.
Ulnar styloid fractures
The distal radioulnar ligaments connect the distal radius to
the ulna, inserting via the triangular fibrocartilage complex
(TFCC) to both the fovea and the styloid of the ulna. Because
of this mechanical connection, the ulnar styloid often sustains
some degree of an avulsion fracture when distal radius frac­
tures displace (see Fig. 8.21). Even in cases where the ulnar
styloid is not fractured, avulsion injuries of the TFCC can lead
to instability of the distal radioulnar joint (DRUJ). For this
reason, the stability of this joint should be tested in every case
of distal radius fracture. When instability is detected, it should
be addressed by performing fixation of the styloid fracture, or
by repair of the TFCC attachment in cases without styloid
fracture. In some ways, the ulnar styloid fracture is analogous
to the volar lip avulsion fracture seen in PIP joint hyperexten­
sion injury: it serves as a marker of injury severity, but does
not need to be treated unless instability is present.
Despite evidence of nonunion in many cases, patients
without DRUJ instability do very well without ulnar styloid
fixation.47 Biomechanical studies have shown that DRUJ
Any fracture-related wound more than a tiny puncture should
probably be washed out formally in the operating room to
reduce the risk of osteomyelitis.
Patients with median nerve symptoms that do not improve
after reduction of the fracture should be considered for an
acute carpal tunnel release. It is our experience that these
patients typically have a prolonged recovery due to their
nerve contusion/crush injury, so relieving any ongoing com­
pression of the nerve can be important to their ultimate
recovery. If median nerve symptoms do improve with fracture
reduction, the carpal tunnel should still be released at the time
of surgical fixation.
Operative treatments for distal radius fractures include
percutaneous K-wire fixation, external fixation, internal fixa­
tion, or combinations of these techniques. Internal fixation can
be further subdivided into dorsal plating, volar plating, and
fragment-specific plating configurations.
The introduction of volar fixed-angle plates with locking
screws has revolutionized the treatment of these fractures.33
Historically, the dorsal approach was thought to be safer, as
it avoided the important neurovascular structures found at
the volar wrist. Furthermore, dorsal buttress plates seemed
more logical, since these fractures tend to displace dorsally.
However, dorsal plating was soon found to be associated with
many complications, especially extensor tendon ruptures, due
Fig. 8.19  Disruption of the first Gilula arc as a result of a lunotriquetral ligament
injury.

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CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
Fig. 8.20  (A) Lateral X-ray showing perilunate dislocation. (B) Extended carpal tunnel release, showing lunate in the carpal tunnel. L, lunate. (C) Dorsal wrist exposure,
after lunate has been reduced. Note the complete disruption of the scapholunate ligament. C, Capitate; DR, distal radius; H, hamate; L, lunate; S, scaphoid; Tq: triquetrum.
(D) Postoperative X-ray showing bone anchors and protective K-wires across scapholunate, scaphocapitate, and lunotriquetral articulations.
A
B
C
D

185
Future directions
A
Fig. 8.21  (A) A complex distal radius fracture that has been (B) reduced using a
volar locking plate. Note the displacement of the ulnar styloid fracture, which does
not need to be fixated because the distal radioulnar joint is stable with manual
testing.
B
Fig. 8.22  Fluoroscopic 30° offset lateral view, showing that each of the distal
screws is outside the radiocarpal joint.
stability in these cases can be maintained by the distal oblique
bundle of the interosseous membrane.48 This makes it all the
more important to obtain anatomic distal radius reductions,
so that the appropriate tension on the interosseous membrane
is maintained.49
In cases where the DRUJ is unstable, the ulnar styloid can
be fixed with tension-band constructs or small “hook plates”,
which have recently been developed (Fig. 8.23). Hardware in
this location is not particularly dangerous to the nearby
tendons, but is often symptomatic to the patient, since it is on
the subcutaneous border of the wrist and forearm, without
much soft tissue padding to cover the hardware.
Future directions
The problem of scaphoid nonunion with avascular necrosis of
the proximal pole has led to tremendous amounts of research
and innovation over the years. The latest development in this
field is a further refinement of the medial femoral condyle
flap. While the traditional flap was described as an osteoperi­
osteal flap, Drs. Higgins and Burger have developed a version
of the flap that is an osteocartilaginous construct, termed the
medial femoral trochlear flap.50 This free flap can be used to
replace the entire proximal pole of the scaphoid, as long as
one takes the time to precisely “carpenter” the graft to the
correct shape. Although logic dictates that there must be some

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SECTION II
CHAPTER 8 • Fractures and dislocations of the wrist and distal radius
disadvantage to the loss of the scapholunate ligament, it does
not appear that these patients develop automatic instability.
In fact, Dr. Higgins has shown that scapholunate stability can
be effectively restored by “overstuffing” the scaphoid dimen­
sions using a larger-than-anatomic graft to reconstruct this
troublesome carpal bone.51
Treatment of distal radius fractures in the elderly, as men­
tioned before, is still an area where we would like better
outcomes data to guide treatment decisions. It is clear that the
elderly perhaps adapt more easily to malunion, or are
somehow more tolerant of wrist malalignment. Furthermore,
it is not clear which method of fixation (K-wires, external fixa­
tion, or internal fixation) will lead to the most acceptable
Fig. 8.23  Options for ulnar styloid fixation include (A) K-wires, with or without a tension band, and (B) ulnar hook plate, which works well for larger styloid or ulnar head
fractures.
A
B
result. A large, 21-center, international trial is underway (Wrist
and Radius Injury Surgical Trial, or “WRIST”) to help answer
the question of which is the best treatment for this patient
population.52
Bonus images for this chapter can be found online at

Fig. 8.2 Posteroanterior radiograph of the wrist, with carpal bones identified.
Fig. 8.3 Examples of common distal radius fracture eponyms: (A) Colles
fracture, (B) Smith fracture, (C) dorsal Barton fracture, (D) volar Barton fracture,
and (E) Chauffeur fracture.
9. Chung KC, Shauver MJ, Birkmeyer JD. Trends in the United States
in the treatment of distal radial fractures in the elderly. J Bone Joint
Surg Am. 2009;91:1868–1873. This Medicare database study examines
the recent trends in treatment of distal radius fractures in elderly patients.
As internal fixation has become more reliable, we have seen an increase in
its use in this population, though the majority of fractures are still treated
nonoperatively.
13. Kozin SH. Perilunate injuries: diagnosis and treatment. J Am Acad
Orthop Surg. 1998;6:114–120.
26. Davis EN, Chung KC, Kotsis SV, et al. A cost/utility analysis of
open reduction and internal fixation versus cast immobilization for
acute nondisplaced mid-waist scaphoid fractures. Plast Reconstr
Surg. 2006;117:1223–1235, discussion 1236–1238.
28. Buijze GA, Doornberg JN, Ham JS, et al. Surgical compared with
conservative treatment for acute nondisplaced or minimally
displaced scaphoid fractures: a systematic review and meta-analysis
of randomized controlled trials. J Bone Joint Surg Am. 2010;92:1534–
1544. This meta-analysis combined data from several randomized
controlled trials to evaluate surgical versus non-surgical treatment of
acute, non-displaced or minimally displaced scaphoid fractures. The
findings suggest that surgical treatment is favorable with regard to
functional outcome and time off work, but this approach does lead to more
complications than non-operative treatment.
Access the complete reference list online at

187
Future directions
30. Kuo CE, Wolfe SW. Scapholunate instability: current concepts
in diagnosis and management. J Hand Surg Am. 2008;33:998–1013.
31. Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability:
diagnosis and treatment. J Am Acad Orthop Surg. 2000;8:170–179.
This article presents a series of patients with lunotriquetral instability
treated with a variety of reconstructive techniques. It is one of the largest
series on this topic, and the treatment algorithm is thoughtfully presented.
33. Chung KC, Petruska EA. Treatment of unstable distal radial
fractures with the volar locking plating system. J Bone Joint Surg
Am. 2006;88:2687–2694.
40. Sheetz KK, Bishop AT, Berger RA. The arterial blood supply of the
distal radius and ulna and its potential use in vascularized pedicled
bone grafts. J Hand Surg Am. 1995;20:902–914. This anatomic study
presents a detailed, thorough look at the blood supply to the distal radius,
and proposes reliable, pedicled bone flaps based on this data. For many
surgeons, these flaps have become workhorses for carpal reconstruction.
43. Garcia-Elias M, Lluch AL, Stanley JK. Three-ligament tenodesis for
the treatment of scapholunate dissociation: indications and surgical
technique. J Hand Surg Am. 2006;31:125–134. Dr. Garcia-Elias has
enormous experience treating carpal instability, and his approach is
constantly evolving. This article presents a logical, reliable technique as
well as a thoughtful treatment algorithm for these patients.
47. Sammer DM, Shah HM, Shauver MJ, Chung KC. The effect of ulnar
styloid fractures on patient-rated outcomes after volar locking
plating of distal radius fractures. J Hand Surg Am.
2009;34:1595–1602.

187.e1
References
References
1. Chung KC, Spilson SV. The frequency and epidemiology of hand
and forearm fractures in the United States. J Hand Surg Am.
2001;26:908–915.
2. Hove LM. Fractures of the hand. Distribution and relative
incidence. Scand J Plast Reconstr Surg Hand Surg. 1993;27:317–319.
3. Dunn AW. Fractures and dislocations of the carpus. Surg Clin North
Am. 1972;52:1513–1538.
4. Duckworth AD, Jenkins PJ, Aitken SA, et al. Scaphoid fracture
epidemiology. J Trauma Acute Care Surg. 2012;72:E41–E45.
5. Wolf JM, Dawson L, Mountcastle SB, Owens BD. The incidence of
scaphoid fracture in a military population. Injury.
2009;40:1316–1319.
6. Khan IH, Giddins G. Analysis of NHSLA claims in hand and wrist
surgery. J Hand Surg Eur Vol. 2010;35:61–64.
7. Johnson RP. The evolution of carpal nomenclature: a short review.
J Hand Surg Am. 1990;15:834–838.
8. Colles A. On the fracture of the carpal extremity of the radius. Edinb
Med Surg J. 1814;10:182–186.
9. Chung KC, Shauver MJ, Birkmeyer JD. Trends in the United States
in the treatment of distal radial fractures in the elderly. J Bone Joint
Surg Am. 2009;91:1868–1873.
10. Gehrmann SV, Windolf J, Kaufmann RA. Distal radius fracture
management in elderly patients: a literature review. J Hand Surg
Am. 2008;33:421–429.
11. Panagis JS, Gelberman RH, Taleisnik J, Baumgaertner M. The
arterial anatomy of the human carpus. Part II: the intraosseous
vascularity. J Hand Surg Am. 1983;8:375–382.
12. Nagle DJ. Evaluation of chronic wrist pain. J Am Acad Orthop Surg.
2000;8:45–55.
13. Kozin SH. Perilunate injuries: diagnosis and treatment. J Am Acad
Orthop Surg. 1998;6:114–120.
14. Budoff JE. Treatment of acute lunate and perilunate dislocations.
J Hand Surg Am. 2008;33:1424–1432.
15. Kozin SH, Wood MB. Early soft-tissue complications after fractures
of the distal part of the radius. J Bone Joint Surg Am.
1993;75:144–153.
16. Definition of carpal instability. The Anatomy and Biomechanics
Committee of the International Federation of Societies for Surgery
of the Hand. J Hand Surg Am. 1999;24:866–867.
17. International Wrist Investigators’ Workshop Terminology
Committee. Wrist: terminology and definitions. J Bone Joint Surg
Am. 2002;84-A(suppl 1):1–73.
18. Amadio PC, et al. Scaphoid malunion. J Hand Surg Am.
1989;14:679–687.
19. Watson HK, Ashmead DT, Makhlouf MV. Examination of the
scaphoid. J Hand Surg Am. 1988;13:657–660.
20. Kleinman WB. Physical examination of the wrist: useful provocative
maneuvers. J Hand Surg Am. 2015;40:1486–1500.
21. Reagan DS, Linscheid RL, Dobyns JH. Lunotriquetral sprains.
J Hand Surg Am. 1984;9:502–514.
22. Schreibman KL, Freeland A, Gilula LA, Yin Y. Imaging of the hand
and wrist. Orthop Clin North Am. 1997;28:537–582.
23. Goldfarb CA, Yin Y, Gilula LA, et al. Wrist fractures: what the
clinician wants to know. Radiology. 2001;219:11–28.
24. Andersson JK, Andernord D, Karlsson J, Fridén J. Efficacy of
magnetic resonance imaging and clinical tests in diagnostics of
wrist ligament injuries: a systematic review. Arthroscopy.
2015;31:2014–2020.e2.
25. Haisman JM, Rohde RS, Weiland AJ. Acute fractures of the
scaphoid. J Bone Joint Surg Am. 2006;88:2750–2758.
26. Davis EN, Chung KC, Kotsis SV, et al. A cost/utility analysis of
open reduction and internal fixation versus cast immobilization for
acute nondisplaced mid-waist scaphoid fractures. Plast Reconstr
Surg. 2006;117:1223–1235, discussion 1236–1238.
27. Bond CD, Shin AY, McBride MT, Dao KD. Percutaneous screw
fixation or cast immobilization for nondisplaced scaphoid fractures.
J Bone Joint Surg Am. 2001;83-A:483–488.
28. Buijze GA, Doornberg JN, Ham JS, et al. Surgical compared with
conservative treatment for acute nondisplaced or minimally
displaced scaphoid fractures: a systematic review and meta-analysis
of randomized controlled trials. J Bone Joint Surg Am.
2010;92:1534–1544.
29. Dias JJ, Wildin CJ, Bhowal B, Thompson JR. Should acute scaphoid
fractures be fixed? A randomized controlled trial. J Bone Joint Surg
Am. 2005;87:2160–2168.
30. Kuo CE, Wolfe SW. Scapholunate instability: current concepts in
diagnosis and management. J Hand Surg Am. 2008;33:998–1013.
31. Shin AY, Battaglia MJ, Bishop AT. Lunotriquetral instability:
diagnosis and treatment. J Am Acad Orthop Surg. 2000;8:170–179.
32. Lichtman DM, Bindra RR, Boyer MI, et al. Treatment of distal
radius fractures. J Am Acad Orthop Surg. 2010;18:180–189.
33. Chung KC, Petruska EA. Treatment of unstable distal radial
fractures with the volar locking plating system. J Bone Joint Surg
Am. 2006;88:2687–2694.
34. Orbay JL, Fernandez DL. Volar fixed-angle plate fixation for
unstable distal radius fractures in the elderly patient. J Hand Surg
Am. 2004;29:96–102.
35. Young BT, Rayan GM. Outcome following nonoperative treatment
of displaced distal radius fractures in low-demand patients older
than 60 years. J Hand Surg Am. 2000;25:19–28.
36. Grewal R, MacDermid JC. The risk of adverse outcomes in
extra-articular distal radius fractures is increased with
malalignment in patients of all ages but mitigated in older patients.
J Hand Surg Am. 2007;32:962–970.
37. Chung KC. A simplified approach for unstable scaphoid fracture
fixation using the Acutrak screw. Plast Reconstr Surg.
2002;110:1697–1703.
38. Kozin SH. Incidence, mechanism, and natural history of scaphoid
fractures. Hand Clin. 2001;17:515–524.
39. Kawamura K, Chung KC. Treatment of scaphoid fractures and
nonunions. J Hand Surg Am. 2008;33:988–997.
40. Sheetz KK, Bishop AT, Berger RA. The arterial blood supply of the
distal radius and ulna and its potential use in vascularized pedicled
bone grafts. J Hand Surg Am. 1995;20:902–914.
41. Jones DB Jr, Moran SL, Bishop AT, Shin AY. Free-vascularized
medial femoral condyle bone transfer in the treatment of scaphoid
nonunions. Plast Reconstr Surg. 2010;125:1176–1184.
42. Szabo RM. Scapholunate ligament repair with capsulodesis
reinforcement. J Hand Surg Am. 2008;33:1645–1654.
43. Garcia-Elias M, Lluch AL, Stanley JK. Three-ligament tenodesis for
the treatment of scapholunate dissociation: indications and surgical
technique. J Hand Surg Am. 2006;31:125–134.
44. Wagner ER, Elhassan BT, Rizzo M. Diagnosis and treatment of
chronic lunotriquetral ligament injuries. Hand Clin. 2015;31:
477–486.
45. Mirza A, Mirza JB, Shin AY, et al. Isolated lunotriquetral ligament
tears treated with ulnar shortening osteotomy. J Hand Surg Am.
2013;38:1492–1497.
46. Chung KC, Petruska EA. Treatment of unstable distal radial
fractures with the volar locking plating system. Surgical technique.
J Bone Joint Surg Am. 2007;89(suppl 2 Pt. 2):256–266.
47. Sammer DM, Shah HM, Shauver MJ, Chung KC. The effect of ulnar
styloid fractures on patient-rated outcomes after volar locking
plating of distal radius fractures. J Hand Surg Am.
2009;34:1595–1602.
48. Moritomo H. The distal interosseous membrane: current concepts
in wrist anatomy and biomechanics. J Hand Surg Am.
2012;37:1501–1507.
49. Ross M, Di Mascio L, Peters S, et al. Defining residual radial
translation of distal radius fractures: a potential cause of distal
radioulnar joint instability. J Wrist Surg. 2014;3:22–29.
50. Higgins JP, Burger HK. Proximal scaphoid arthroplasty
using the medial femoral trochlea flap. J Wrist Surg. 2013;2:
228–233.
51. Capito AE, Higgins JP. Scaphoid overstuffing: the effects of the
dimensions of scaphoid reconstruction on scapholunate alignment.
J Hand Surg Am. 2013;38:2419–2425.
52. Wrist and Radius Injury Surgical Trial (WRIST) Study Group.
Reflections 1 year into the 21-Center National Institutes of Health–
funded WRIST study: a primer on conducting a multicenter clinical
trial. J Hand Surg Am. 2013;38:1194–1201.

SECTION II • Acquired Traumatic Disorders
9 
Flexor tendon injuries and reconstruction
Jin Bo Tang
SYNOPSIS
■ Tendons transmit forces generated by muscles to move joints or to
create action power. Flexor tendon injuries are common, but recovery
of satisfactory function, particularly after injuries within the digital
sheath, is sometimes difficult. Lacerated flexor tendons should be
treated by primary surgical repair whenever possible.
■ The current trend of end-to-end surgical tendon repairs is to use
multistrand core sutures (four-strand repairs such as cruciate, double
Tsuge, Strickland, modified Savage, or six-strand repairs such as
modified Savage, Tang, or triple Kessler).
■ In tendon repairs in the digital sheath area, a number of surgeons
advocate that the A2 pulley can be released up to two-thirds of its
length, and the A4 pulley can be entirely released when necessary and
tendon repair is in the proximity of the pulley, given the integrity of the
other pulleys. The release may reduce the resistance to tendon motion
and the chance of repair ruptures. This technique is somewhat
controversial.
■ Postoperatively, early tendon mobilization should always be employed,
except in children or in some rare instances; motion protocols vary
greatly among different treatment centers.
■ Repair rupture, adhesion formation, and joint stiffness are major
complications of primary surgery.
■ Combined use of multistrand core repairs, release of constricting
pulley parts, and well-designed postoperative combined passive and
active motion protocols – that do not overload, but sufficiently move
the tendon – can help minimize adhesions, avoid repair ruptures, and
restore optimal function. Full extension and flexion of the operated digit
should be tested right after repair, ideally in a wide-awake setting, to
ascertain no gapping of the repair and smooth tendon gliding.
■ Secondary surgeries include tenolysis, free tendon grafting, and staged
tendon reconstruction. Tenolysis is indicated when restricting
adhesions hamper tendon gliding and soft tissues and joint conditions
of the hand are favorable. Free tendon grafting is a salvage operation
for failed primary repairs, delayed treatment (>1 month) of an acute
cut, or lengthy tendon defects. Staged reconstruction is indicated in
case of extensive scar formation or multiple failed surgeries.
Preservation or reconstruction of major annular pulleys is vital to
restoring function of the digits during these secondary surgeries.
■ Closed rupture of flexor tendons usually requires surgical repair.
■ Success of flexor tendon surgery is very expertise-dependent. A
thorough mastery of anatomy and meticulous surgical technique are
requirements for satisfactory restoration of function.
Introduction
Tendons are composed of dense connective tissues that trans­
mit forces generated by muscles to move the joints or to create
action power. Functionally, the hand is dependent upon the
integrity and ample gliding of the tendons. Among all the
tendons in the body, those in the hand are most frequently
injured, due to their length and the varied nature of the activi­
ties of the hand. The pursuit of ideal repair techniques has
drawn the attention of surgeons ever since hand surgery
became a subspecialty. For over a century, flexor tendon
repairs have presented challenges to hand surgeons.
Difficulties in restoration of function of digital flexor
tendons relate chiefly to the intricate anatomy of flexor tendon
systems: the coexistence of superficialis and profundus
tendons within a tight fibro-osseous tunnel. Peritendinous
adhesions jeopardize tendon gliding. Tendons within the
synovial sheath (intrasynovial tendons) were once considered
to lack self-reparative capacity; therefore, ingrowth of adhe­
sions from peritendinous tissues was believed to be a prereq­
uisite in the tendon healing process.1–4 As the concepts
regarding tendon healing biology evolved, tendon cells have
been proven capable of proliferating and of producing colla­
gen to heal tendons.5–10 However, the tendon is innately low
in cell density and growth factor activity, limiting its early
healing strength.
In the early and middle 20th century, secondary tendon
grafting dominated the repair of digital flexor tendons. During
this period, tendon implants were developed for staged
tendon reconstruction. However, as the practice of primary
repair prevailed in recent decades, the number of cases indi­
cated for secondary tendon grafting or staged reconstruction
  Access video content for this chapter online at expertconsult.com

189
Basic science
Basic science
Anatomy
There are 12 flexor tendons in the hand and forearm region.
They include finger and thumb flexors and wrist flexors.
Finger flexor tendons are the flexor digitorum superficialis
(FDS) and the flexor digitorum profundus (FDP), and the
tendon in the thumb is the flexor pollicis longus (FPL). They
originate from muscles at about the mid forearm. The tendons
of the FDP, except the index finger, come from a common
muscle belly. The tendons of the FDS originate from the sepa­
rate muscle bellies, which allow more independent finger
flexion. The FPL tendon arises from the volar aspect of the
midportion of the radial shaft and from its adjacent interosse­
ous membrane. Three wrist flexors are flexor carpi radialis
(FCR) and ulnaris (FCU), and palmaris longus. Palmaris
longus is absent in about 15–20% of the normal population.
Wrist flexion power is not affected by absence of this muscle.
Within the carpal tunnel, nine tendons exist – four FDS,
four FDP, and one FPL. The relationship of these tendons
within the carpal tunnel is fairly constant. The FDS tendons
to the ring and middle fingers lie superficially, deeper are the
FDS tendons to the index and small fingers, and deeper still
are the FDP tendons. The FPL tendon is located deep and
radially adjacent to the scaphoid and the trapezium. After
emerging from the carpal tunnel, the tendons enter the palm.
At about the level of the superficial palmar artery arch, the
lumbrical tendons originate from the FDP tendons.
The most intricate portions of the flexor tendons are within
the fingers, where the tendons glide within a closed fibro-
osseous sheath with segmental, semirigid, constrictive dense
connective tissue bands present. The digital sheath forms a
closed synovial compartment extending from the distal palm
to the middle of the distal phalanx. Proximally, the synovial
sheath ends just proximal to the neck of the metacarpus,
forming the proximal reflection of the digital flexor sheath.
The FDS tendons lie superficial to the FDP tendons up to the
bifurcation of the FDS tendon at the midportion of the proxi­
mal phalanx. Then, FDS tendons become two slips coursing
laterally and then deeper to the FDP tendons. This FDS bifur­
cation is in the A2 pulley area. This part of the FDS tendon
also serves to constrain the FDP tendon; the FDS segment at
bifurcation may be viewed as a structure functioning similarly
to a pulley. Deep to the FDP tendon, the FDS slips rejoin to
form Camper’s chiasm (a fibrous interweaved connection
between two FDS slips), and distally insert on the proximal
and middle parts of the middle phalanx as two separate slips.
The FDP tendon inserts into the volar aspect of the distal
phalanx. The FPL tendon is the only tendon inside the flexor
sheath of the thumb and inserts at the distal phalanx.
The digital flexor sheath consists of synovial sheath and
interwoven condensed fibrous bands (“pulleys”). Synovial
sheath is a thin layer of continuous smooth paratenon cover­
ing the inner surface of the fibrous sheath, providing a
smooth surface for tendon gliding and nutrition to the
tendons. The pulley system of the digital flexor tendon is
unique; it consists of annular pulleys (condensed, rigid, and
heavier annular bands) and cruciate pulleys (filmy cruciform
bands) (Fig. 9.1).151 There are five annular pulleys (A1–A5),
three cruciate pulleys (C1–C3), and one palmar aponeurosis
decreased drastically. Primary repair of injured digital flexor
tendons was pioneered by Verdan11 and Kleinert et al.12 in the
1960s and is the essential approach underlying current prac­
tice. Current primary repair and early tendon motion are
based on the recognition of intrinsic healing capacity of the
tendon in the 1970s and 1980s by Lundborg, Manske et al., and
Gelberman et al.5–10
Nevertheless, despite the widespread use of primary repairs,
surgical outcomes remained unpredictable, and sometimes
even disappointing. In the last two to three decades, major
efforts were thus devoted to tackling this problem, with the
goal of achieving consistently optimal outcomes and minimiz­
ing repair ruptures and adhesions. In this regard, a number of
multistrand core surgical repairs – such as Savage, Strickland,
cruciate, Lim–Tsai, or Tang techniques13–19 – have been devel­
oped to replace weaker, conventional two-strand repairs.
Subdivisions of zones 1 and 2 of digital flexor tendon systems
were proposed by Moiemen and Elliot20 and Tang,21 which
offer precise nomenclature in recording the locations of tendon
cuts, discussing treatments, and comparing outcomes. Surgi­
cal procedures to release critical parts of the pulleys have been
advocated by Tang22 and Kwai Ben and Elliot23 to decompress
the tendon and “free” tendon motion. In the past few years,
we have witnessed reports in which repair ruptures have been
minimized, with recovery of excellent or good function in the
majority of cases.19,24,25 These recent reports represent some
remarkable steps towards satisfactory flexor tendon repairs
and highlight the promise of predictable tendon repairs
(Box 9.1).
Access the Historical Perspective section online at

BOX 9.1  General tips for surgeons of flexor tendon repairs
1. Repairing flexor tendons is based on a thorough mastery of
anatomy and biomechanics. The surgeon should know the
anatomy in detail, including the lengths of major pulleys,
characteristic changes in the diameter of the sheath, and
tendon gliding amplitude.
2. Primary repairs should be performed by experienced surgeons
whenever possible.
3. Mastery of atraumatic techniques is essential for the operator.
The outcomes of the repairs are very expertise-dependent;
repair of tendons by an inexperienced surgeon is a frequent
cause of tendon adhesions and poor function, and thus should
be avoided.
4. Conventional two-strand repairs are weak; stronger surgical
repairs are preferable.
5. Complete closure of the tendon sheath is not necessary. Venting
of a part of sheath (<2.0 cm), including a critical portion of the
pulleys, provides easy access to the injured tendons, and may
decrease resistance to tendon gliding after surgery; this
procedure does not lead to loss of digital function when other
sheath parts are intact.
6. Surgeons should emphasize strong suture techniques and
decreasing compression to the tendons, which will aid in
achieving improved outcomes with hand therapy.

189.e1
Historical perspective
Historical perspective
Documentation and treatment of tendon injuries dates back
to antiquity. Hippocrates and other ancient physicians
observed a white slender tubular structure entering skeletal
muscle, and considered it as a nerve. Galen, who lived in the
Roman Empire in the second century, advised physicians not
to repair tendons because it was believed to result in pain,
twitching, and convulsions of the limb. Over the following 15
centuries, surgeons were largely influenced by the teaching of
Galen. The seminal challenge to Galen’s assertion did not
occur until the mid-eighteenth century when Von Haller
showed that the placement of a suture in canine Achilles
tendons did not have detrimental effects.26
The first experimental investigation of the tendon healing
process was performed in 1767 by John Hunter, who recorded
that the canine Achilles tendon healed by the formation of
callus, similar to that seen in healing bone.26,27 However,
specific studies of the flexor tendon healing within digital
sheath were not started until about 150 years later, in the early
twentieth century. Around 1920, Bier and Saloman observed
poor tendon healing of sutured canine flexor tendons.28
Saloman thus advocated to leave a defect in the tendon sheath
which allowed contact between the repaired tendon and the
subcutaneous tissue. Bunnell and Garlock observed frequent
occurrence of restrictive adhesions at the flexor tendon lacera­
tion site.29–32 Bunnell coined the term “no man’s land” to
describe the region where the flexor tendons passed through
the digital sheath and advised surgeons to be cautious when
repairing tendons within this region. In 1940, Mason advised
some specific conditions for repairing lacerated digital flexor
tendons, which included never repairing both tendons, wide
excision of the overlying sheath, and adequately eliminating
contaminates from the wound.33 Because of the generally
unsatisfactory results of primary flexor tendon repairs, many
surgeons preferred tendon grafting, despite the fact that a
few surgeons had demonstrated that primary surgeries were
practicable at that time.
In the early half of the 20th century, repairing the lacerated
tendons within the digital sheath was predominantly by
means of secondary tendon grafting. The first series of flexor
tendon grafts in the hand was reported by Lexer in 1912.34 He
used grafts to repair flexor tendons after rupture, old lacera­
tions, infections and cases with ischemic contracture. In 1916,
Mayer published articles that have served as the basis of the
present day concepts of free tendon grafting.35–37 He empha­
sized the need for existing surgical techniques, direct juncture
of the tendon to bone, the use of adequate muscle as a motor,
and preserving peritenon around a graft to lessen adhesions.
In 1918, Bunnell published a classic article on tendon grafting
in which atraumatic technique, a bloodless field, perfect
asepsis, and preservation of pulleys were emphasized.30 The
surgical techniques of tendon grafting were subsequently
modified by various leaders in the field, including Pulvertaft,
Graham, Littler, Boyes and Stark.38–42
In an effort to combat serious scarring in the tendon gliding
bed in which conventional one-stage free tendon graft likely
failed to restore tendon function, various materials have been
implanted into the fingers to stimulate formation of a smoother
tendon gliding bed. In 1936, Mayer inserted a celloidin tube
into seriously scarred tendon gliding bed, and after 4 to 6
weeks of implantation he then introduced a tendon graft.43
Mayer brought forth the pseudosheath concept. In the 1950s,
Bassett and Carroll began working with flexible silicone
rubber rods to build pseudosheaths in badly scarred fingers,
adding passive motion into this procedure.44 This method was
later refined into a two-stage tendon reconstruction by Hunter
et al. in the 1960s.45 Hunter et al. also developed the active
tendon implant.46 These implants and two-stage reconstruc­
tion procedures are still used currently, effective for those
patients with badly scarred digits and serving as a salvage
procedure after other surgery attempts failed.
It was not until the 1960s that reports of surgical techniques
and outcomes of primary repair from Verdan,11 and Kleinert
et al.12 became the turning point in establishing the practice of
primary repair of digital flexor tendons. The emerging popu­
larity of primary tendon repair stimulated experimental
studies to elucidate mechanisms of the healing process. In the
1970s and 1980s, Manske et al. demonstrated diffusion of
nutrients through synovial fluid to be an effective source
of nutrition of intrasynovial tendon, thus obviating the need
of vascularization in the healing process.47–50 Matthews and
Richards observed healing of lacerated rabbit flexor tendons
within the intact digital sheath in the absence of adhesions.5,51–54
Lindsay et al. noted that both epitenon and endotenon cells
proliferate and migrate to the laceration site, subsequently
bridging it.5,55–57 Lundborg et al. demonstrated healing of lac­
erated flexor tendon segments when placed within the syno­
vial environment of the knee joint or in a synthetic membrane
pouch placed in a subcutaneous pocket of the back of the
rabbit.6,7 In the 1980s, Manske, Lesker, Gelberman, and Mass
et al. demonstrated healing of lacerated flexor tendon seg­
ments of different animals when placed in tissue culture in
the complete absence of extrinsic cells.9,10,58–61
In the last three decades, major advancements in the field
of flexor tendon repairs were made with respect to the devel­
opment of novel surgical repair techniques, accumulation
of biomechanical information regarding tendon repairs or
gliding mechanisms, modifications of postsurgical rehabilita­
tion methods, and an emerging trend of exploring biological
approaches to enhance tendon healing. In 1985, Savage13
published an influential experimental study that later stimu­
lated a widespread interest in developing multistrand suture
techniques to repair the tendon.62–74 The cruciate repair, a
simple yet strong four-strand repair developed by McLarney
et al.16 in the late 1990s, is used in many hand centers. In the
same period, multistrand repair using Tsuge’s looped suture
lines, as developed by Lim and Tsai, Tang (and its modifica­
tion, M-Tang method),17–19,68 were used by surgeons in hand
centers in Asia, Europe, and North America. In 1995 and 1998,
Tang22 and Elliot23 presented an anatomical study and clinical
results of the release of a major flexor pulley (A2) to accom­
modate gliding of the repaired tendons, respectively. Elliot
and Tang also proposed to vent the A4 pulley when the tendon
repairs are in the areas.19,23
The flexor tendons were divided into five zones by Verdan
in the 1960s. In the 1990s, subdivisions of zone 1 by Moiemen
and Elliot20 and zone 2 by Tang21 were added into the existing
zoning system, in order to describe the location of injuries
and repairs more specifically. These zoning and sub-zoning
systems provide hand surgeons with the nomenclature to
document the tendon injuries and outcomes, and discuss the
principles of treatment.

189.e2
SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
In the past 30 years, biomechanics of the flexor tendon
system has become a subject of intense interest for both sur­
geons and basic scientists. A large volume of information
regarding tendon gliding and repair biomechanics has been
obtained,74–122 including surgical repair techniques (mainly
from labs of Gelberman, Manske, Mass, McGrouther, Tang,
Trumble, and Wolfe), gliding resistance of tendons within
the sheath or against annular pulleys (Amadio and Tang),
mechanics of the pulleys (Amadio, Mass, and Tang), postsur­
gical rehabilitation (Amadio and Boyer), and edema formation
(Tang). In recent years, as advocated by Lalonde,123,124 flexor
tendon repair and tenolysis are popularly performed in some
centers around the globe under wide-awake settings (without
tourniquet) with local anesthesia plus epinephrine. This
approach allows the tendon to move actively during surgery
to ascertain good quality of tendon repair or tenolysis.
In the past two decades, investigations exploring molecular
events in the tendon healing process, tendon tissue engineer­
ing, and biological approaches to enhance the healing came
into the center stage of basic science investigations. Chang
et al. reported a series of investigations exploring function
of growth factors in tendon healing, molecular methods to
prevent adhesions, and tendon tissue engineering.125–135 Tang
and colleagues performed a series of studies of molecular
events in tendon healing and gene therapy approaches to
enhance the strength or to limit adhesions.136–145
Comprehensive history and development of flexor tendon
repairs were covered in more detail in the reviews written by
Verdan (1972),146 Manske (1989),147 Strickland (1995),148 Elliot
(2003),149 Manske (2005),26 and Tang (2007)19 and Tang et al
(2014).150

190
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CHAPTER 9 • Flexor tendon injuries and reconstruction
middle and distal parts of the A2 pulley. The A2 and A4
pulleys are easily recognizable, because both are remarkably
denser and more rigid than their adjacent flexor sheath. The
A1 pulley, with a length of about 1.0 cm, is located proximal
to the A2 pulley; in some instances, both A1 and A2 pulleys
merge to form an especially lengthy pulley complex. The A3
pulley is located palmar to the PIP joint, but it is very short
(0.3 cm) and may be difficult to distinguish from the synovial
sheath.
In the thumb, there are three pulleys (A1, oblique, and A2)
with no cruciate pulleys (Fig. 9.2). The A1 and oblique pulleys
are functionally important. The A1 pulley, 0.7–0.9 cm long, is
located palmar to the MCP joint. The oblique pulley, 0.9–1.1 cm
long, spans the middle and distal parts of the proximal
phalanx. The A2 pulley is near the site of insertion of the FPL
tendon, which is thin and 0.8–1.0 cm long.
The FDP tendon has two vincula: a fan-like short vinculum
and a cord-like long vinculum. The short vinculum is located
at the insertion of the FDP tendon (Fig. 9.3). The long vincu­
lum connects the FDP tendon through the short vinculum of
the FDS tendon to the floor of the palmar surface of the
phalanges. The FDS tendon also has two vincula; one connect­
ing to the proximal phalanx, and another at the insertion of
the FDS tendon. Vincula carry blood vessels to the dorsum of
these tendons, providing limited nutrition. Tendon insertion
sites to bones also carry vessels into tendons over a very short
distance.
According to anatomical features, the flexor tendons in the
hand and forearm are divided into five zones, which offers
pulley.151,152 The A1, A3, and A5 pulleys originate from the
palmar plates of the metacarpophalangeal (MCP), proximal
interphalangeal (PIP) and distal interphalangeal (DIP) joints,
and the A2 and A4 pulleys originate from the middle portion
of the proximal and middle phalanges, respectively. The
broadest annular pulley is the A2 pulley, which covers the
proximal two-thirds of the proximal phalanx and encompasses
the bifurcation of the FDS tendon at its middle part. The A4
pulley is located at the middle third of the middle phalanx.
The A2 and A4 pulleys are the largest among five annular
pulleys and have the most important function. The annular
pulleys maintain the anatomical paths of tendons close to
bones and phalangeal joints, thus optimizing the mechanical
efficiency of digital flexion. The more compressible cruciate
pulleys allow for digital flexion to occur with condensation of
the fibro-osseous sheath at the inner part of flexed fingers.
This is called the “concertina effect”.
The length of the A2 pulley is about 1.5–1.7 cm in the
middle finger of an average adult, and the length of the A4
pulley is about 0.5–0.7 cm. The diameter of the flexor sheath
is at its narrowest at the level of the A4 pulley and in the
Fig. 9.1  Annular pulleys (condensed, rigid, and heavier annular bands) and
cruciate pulleys (filmy cruciform bands) are present in the fingers. There are five
annular pulleys (A1–A5), three cruciate pulleys (C1–C3), and one palmar
aponeurosis (PA) pulley.
A5
A4
A3
A2
A1
Transverse metacarpal ligament
Vertical septa
Palmar
aponeurosis
C3
C2
C1
Fig. 9.2  Locations of flexor pulleys of the thumb. There are three pulleys in the
thumb: A1, oblique, and A2 pulley, from distal to proximal.
A2
A1
Oblique pulley
Abductor pollicis
Flexor (deep head)

191
Basic science
■ Zone 4: Area covered by the transverse carpal ligament
■ Zone 5: Proximal to the transverse carpal ligament
In the thumb, zone 1 is distal to the interphalangeal (IP) joint,
zone 2 is from the IP joint to the A1 pulley, and zone 3 is the
area of the thenar eminence.
The subdivisions of zone 1 by Moiemen and Elliot are:
■ 1A: the very distal FDP tendon (usually <1 cm)
■ 1B: from zone 1A to distal margin of the A4 pulley
■ 1C: the FDP tendon within the A4 pulley
The subdivisions of zone 2 by Tang are:
■ 2A: the area of the FDS tendon insertion
■ 2B: from the proximal margin of the FDS insertion to the
distal margin of the A2 pulley
■ 2C: the area covered by the A2 pulley
Fig. 9.3  Insertions and relative positions of the flexor digitorum superficialis (FDS)
and flexor digitorum profundus (FDP) tendons and vincula. Each of the FDS and
FDP tendon has two vincula, one short and one long. The relation of the FDS and
FDP tendons are complex in the middle part of the proximal phalanx under the A2
pulley (zone 2C).
IID
IIC
IIB
FDP tendon
Vinculum longus
FDS tendon
Vincula brevia
Vinculum brevia
Vinculum longus
A
B
Fig. 9.4  Divisions of the flexor tendons into five zones according to anatomical
structures of the flexor tendons, presence of the synovial sheath, and the transverse
carpal ligament.
1
1
2
2
3
3
4
5
Fig. 9.5  Subdivisions of zones 1 and 2 of flexor tendons
in the fingers and their relations to the flexor pulleys.
Subdivision of zone 1
(Moiemen and Elliot)
Subdivision of zone 2
(Tang)
1A
2A
2B
2C
2D
1B
1C
the fundamental nomenclature for flexor tendon anatomy and
surgical repairs.153 In the 1990s, the most complex areas –
flexor tendons in the digital sheath – were subdivided by
Moiemen and Elliot,20 and by Tang.21 The zoning is described
below, and its relation to the locations of pulleys is shown in
Figs. 9.4 and 9.5:
■ Zone 1: from the insertion of the FDS tendon to the
terminal insertion of the FDP tendon
■ Zone 2: from the proximal reflection of the digital
synovial sheath to the FDS insertion
■ Zone 3: from the distal margin of the transverse carpal
ligament to the digital synovial sheath

192
SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
visible, filmy, and membranous tissue from tendon to outside
tissues; (3) loose adhesions: loose and largely movable; (4)
moderately dense adhesions: of limited mobility; and (5)
dense adhesions: dense, almost immovable, and invading
deep into the tendon.
The first two grades do not affect tendon motion; the third
affects motion mildly. Because the fourth and fifth affect
motion dramatically, those are the adhesions that surgeons
seek to prevent. The density of adhesions relates to the tissues
from which they arise. The adhesions arising from bones,
periosteum, or major annular pulleys are dense. The density
of adhesions can be altered to some extent by tendon motion.
Some adhesion fibers can be disrupted as well. Surgeons
should do their utmost to preclude or minimize the formation
of adhesions that will restrict tendon gliding.
Many strategies have been attempted or suggested to
prevent adhesion formations, including medications, use of
artificial or biological barriers, and chemical or molecular
approaches, with varied results. However, few medications or
barriers have become clinically routine. So far, the most effec­
tive methods to prevent adhesions in clinic are meticulous
surgery and early postoperative motion; the prime cause of
adhesions is tendon repair by inexperienced surgeons.
Biomechanics of tendon repairs and gliding
Forces generated during normal hand action range from 1 to
35 N, except tip pinch, according to in vivo measurements.154
Therefore, a surgically repaired tendon should be able to
withstand a tension of at least 40 N during motion, with
power sufficient to resist gap formation. The repair should be
able to withstand cyclic loads under both linear and curvilin­
ear load conditions. Laboratory tests have shown that conven­
tional two-strand core repairs plus running peripheral sutures
yield a maximal strength from 20 to 30 N;93 this is lower than
forces generated during normal hand actions and explains
why some repairs are disrupted during postoperative motion
exercise. Studies showed that failure forces of four-strand
repairs are around or beyond 40 N;16,65,94 six-strand repairs fail
with loads over 50–60 N.13,71,85
Many factors affect the strength of a surgical repair (Fig.
9.6): (1) the number of suture strands across the repair sites
– strength is roughly proportional to the number of core
sutures;74–76,81–83,85,94–97 (2) the tension of repairs – most relevant
to gap formation and stiffness of repairs;19,98 (3) the core suture
purchase;84,86,88,94 (4) the types of tendon–suture junction –
locking or grasping;79,88,95,97 (5) the diameter of suture locks
in the tendons – a small-diameter lock diminishes anchor
power;80,91 (6) the suture calibers (diameter);82,116,117 (7) the
material properties of suture materials;95,155 (8) the peripheral
sutures,156,157 (9) the curvature of tendon gliding paths – the
repair strength decreases as tendon curvature increases;89,90
and (10) above all, the holding capacity of a tendon, affected
by varying degrees of trauma and post-traumatic tissue soft­
ening, plays a vital role in repair strength.
To achieve an optimal surgical repair, the above-outlined
factors must be considered and incorporated into repair
design. A core suture purchase of at least 0.7 to 1.0 cm is neces­
sary to generate maximal holding power, as recommended by
Tang et al.86,93 and Cao et al.94 Slight tension in the core sutures
is necessary to resist gapping at the repair site.98 A locking
tendon–suture junction is generally better than a grasping
■ 2D: from the proximal margin of the A2 pulley to the
proximal reflection of the digital sheath
Flexor tendon healing
Flexor tendons derive nutrition from both synovial and
vascular sources. Flexor tendons outside the synovial sheath
are supplied with a segmental vascular network through the
paratenon, and the vascular supply plays an important role in
nutrition of these tendons. However, the tendons within the
synovial sheath are mostly deprived of a vascular network.
Only limited dorsal regions around vincular insertions
are vascularized. A series of experiments by Manske et al.
showed that intrasynovial flexor tendons are nourished by
synovial fluid and that nutrition through vascular supplies
is insignificant.47–50 While the general healing process of the
tendon has long been recognized as having early inflamma­
tory, middle collagen production, and late remodeling phases,
the healing potential of the intrasynovial flexor tendon was
a subject of intense investigations and debate over several
decades in late 20th century.1–10,52–61
Before the 1970s, it was widely accepted that the digital
flexor tendon lacked intrinsic healing capacity.1–4 However,
in subsequent decades, the intrinsic healing capacity of the
tendon came to light in a series of elegant experimental
studies. These experiments by Matthews, Lundborg, Manske,
Gelberman, and Mass and others, included observation of the
repair process in lacerated flexor tendons within the synovial
sheath, investigation of cellular activity in the lacerated
tendon within the knee joint, detection of cellular activity, and
the ability to produce matrix by in vitro tendon cultures.5–10,51–61
The work led to the well-supported conclusion that cells in
the intrasynovial tendon can proliferate and participate in the
healing process, making the tendon itself capable of healing
without forming adhesions. This became the scientific basis
of early postoperative tendon mobilization.
It is now agreed that intrasynovial flexor tendons can heal
through two mechanisms – intrinsic and extrinsic. Intrinsic
healing takes place through the proliferation of tenocytes and
production of extracellular matrix by intrinsic cells. Growth
of tissues or cell seeding from outside the tendon is extrinsic
healing. The tendon’s intrinsic healing capacity is innately
weak; extrinsic healing becomes dominant when intrinsic
healing capacity is disabled (such as in the case of severe
trauma to the tendon or peritendinous tissues) or under
conditions (such as postsurgical immobilization) favoring
extrinsic healing. Tendon healing exclusively through the
intrinsic healing mechanism occurs only under a few experi­
mental conditions.7–9 Clinically, the lacerated tendon heals
through a combination of both intrinsic and extrinsic mecha­
nisms, whose balance depends upon the condition of the
tendon and surrounding tissues. Extrinsic healing may act on
the tendon healing process through either forming adhesions
or seeding of the extrinsic cells without adhesions to lacera­
tion site. On the other hand, adhesions do not necessarily
consist of extrinsic cells. Tenocytes may migrate out of the
laceration site for a very limited distance to become part of
adhesions. Conceptually, extrinsic healing does not equal
adhesion formation. However, it is extrinsic healing in the
form of restrictive adhesions that hampers tendon function.
The following five variants (grades) of adhesions are seen
clinically: (1) no adhesions; (2) filmy adhesions: formation of

193
Basic science
Fig. 9.7  Different tendon–suture junctions in tendon repairs: locking and grasping
junctions
Cross-lock (embedded)
Cross-lock (exposed)
Circle-lock
Loop-lock
Pennington lock
Grasp (nonlock)
Fig. 9.6  Factors affecting the surgical repair strength of the
tendon.
Strands: 2, 4, 6 or 8
Suture purchase length
Tension of repair
Suture caliber
Locking or grasping anchor
A Core suture
Holding capacity of tendon
tissue (degrees of trauma
and softening of tendon)
E
Number of runs
Suture purchase
Caliber and tension
B Peripheral suture
Material properties
of sutures
C
Curvature of the
gliding path
D
Repair strength
Factors affecting surgical repair strength
Material strength of suture
junction in terms of holding power. Diameter of the suture
locks must reach or exceed 2 mm, according to Xie et al.91 Tan
and Tang recommend a greater core suture purchase (>1.2 cm)
and locking repairs for an obliquely cut tendon.86–88 Barrie
et al.116 and Taras et al.117 greatly improved repair strength by
increasing suture calibers. Clinically, the caliber of suture used
in adults is either 3-0 or 4-0; sutures of 2-0 or greater are too
large and rigid in the hand.
Tendon–suture junctions in surgical repairs are either
grasping or locking; locking junctions vary greatly (Fig. 9.7).
Grasping repairs are generally weaker than locking repairs.
Among locking junctions, cross-locks provide identical
strength to circle-locks.94 Exposed and embedded cross-locks
create the same strength.92 With an identical number of suture
strands across the tendon, different locking junctions result
in minor differences in the strength. Nevertheless, repairs
with cross- or circle-locks appear slightly stronger than
Kessler-type repairs with Pennington locks. Pennington locks
provide a looser junction than cross- or circle-locks.
Peripheral sutures serve to “tidy up” the approximated
tendon stumps; they may add strength to repairs as
well. Deep-bite peripheral sutures increase repair strength.156
Increases in suture purchase or complex peripheral sutures,
as typified by the Silfverskiöld method,64 increase overall
strength. However, most surgeons choose to insert only
simple peripheral stitches. Some surgeons even do not supple­
ment peripheral stitches when multistrand core sutures have
been used.25 In the presence of a strong multistrand core
repair, peripheral sutures contribute little in terms of strength.
In fact, to simplify repair maneuvers, multistrand core sutures
(with or without a few peripheral sutures) may be sufficient.
In addition to surgical factors, tendon curvature affects
strength as well. Surgical repair in a tendon under a curvilin­
ear load is weaker than that under a linear load; the repair
strength decreases as the curvature increases.89,90 Mechani­
cally, a tendon under linear tension is pulled without being
bent, whereas a tendon under curvilinear tension is subjected
to both linear pulling and bending forces. Therefore, the repair
fails more easily in the flexed finger under curvilinear loads.
When the finger moves to approach full flexion, a strongly
bent tendon is particularly prone to fail (Fig. 9.8).
Annular pulleys are critical to the function of the digital
flexor tendons. The pulleys keep the tendons’ course close
to the phalanges for optimal mechanical efficiency of tendon
excursion. Lengthy loss of the sheath and pulleys causes
anterior displacement – bowstringing – of the flexor tendon
during finger flexion. In fingers, the A2 and A4 pulleys are
most critically located and functionally important. Preserva­
tion or reconstruction of the two pulleys is necessary in the
absence of other pulleys or sheath. Nevertheless, given the
presence of other pulleys and sheath, loss of any individual
pulleys – including the A2 or A4 pulley – appears to result
in few detrimental consequences. Both Tang22 and Tomiano
et al.111,112 showed that incision of the A2 pulley up to one-half
or two-thirds of its length or of the entire A4 pulley results in
no tendon bowstringing and little loss of digital flexion. In in
vivo settings, incision of the A2 pulley decreases resistance to

194
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CHAPTER 9 • Flexor tendon injuries and reconstruction
exposure of suture materials; (4) increases in tendon bulkiness
due to placement of sutures; (5) tight closure of sheath or
pulleys that narrows the tendon gliding tunnel; (6) tendon-
catching at pulley or sheath edges; (7) postsurgical extensor
tethering and joint stiffness that burden the movement of the
flexor tendon; and (8) adhesions that restrict tendon gliding.
Following trauma and surgery, tendons undergo inflam­
mation, healing, and edema. The volume of the tendons is
increased, which increases the resistance within the narrow
sheath tunnel. Subcutaneous edema outside the sheath also
impedes tendon motion. These factors affecting the resistance
to tendon gliding should be considered in deciding how rigor­
ous the postoperative motion program should be. The safety
margin can be enhanced by a strong surgical tendon repair
or appropriately decompressing the tendon to avoid repair
ruptures.
Biological healing strength is a central issue underlying all
tendon repairs. Urbaniak et al.,76 Aoki et al.,77 Kubota et al.78
and Boyer et al.114 have characterized the strengths of the
healing flexor tendon using animal models. They found that
strength either remained consistent or actually decreased
somewhat over the initial few weeks after surgery.76–78
Decreases in strength, typically those in the second postsurgi­
cal week, are thought to be caused by softening of the tendon
stumps, which lower the suture’s holding power. Our inves­
tigations using a chicken model indicated that the strength of
a healing tendon is steady during the initial 4 weeks, followed
by a substantial increase (greater than threefold) in the fifth
and sixth weeks; thereafter, the tendon heals strongly and is
difficult to disrupt. The fifth and sixth weeks after surgery
appear very crucial to regaining strength. Accelerating the
healing, aiming to move this critical “strength gain” period to
earlier weeks, is a current focus of research into molecular
modulation of tendon healing.
Diagnosis
Flexor tendon injuries are open in most cases, resulting from
a sharp cut or a crush, but they can also present as closed
injuries. Open injuries due to extensive trauma are frequently
associated with neurovascular deficits. Closed injuries often
relate to forced extension during active flexion of the finger.
Flexor tendon rupture can also occur as a result of chronic
attrition in rheumatoid disease, Kienböck disease, scaphoid
nonunion, a hamate or a distal radius fracture.
Careful attention to the patient’s history and the mecha­
nism of injury can alert the surgeon to the extent of the tendon
trauma and associated injuries. The natural resting posture of
the wounded digits is important for evaluation. Complete
lacerations of both FDP and FDS tendons are easily diagnosed
when the affected fingers are seen in a relatively extended
position with loss of active finger flexion at PIP and DIP joints.
If the patient can actively flex the DIP joint while the motion
of the PIP joint is blocked, no injuries or only partial injuries
to the FDP tendon can be diagnosed (Fig. 9.9). To assess the
continuity of the FDS tendon, the adjacent fingers are held in
full extension by the examiner. If the patient cannot actively
flex the PIP joint, the FDS tendon is severed completely (Fig.
9.10). Variations of the FDS tendons in the little finger are
frequent. The FDS in 30–35% of the little fingers has a connec­
tion with the FDS in the ring or middle fingers. Some little
tendon motion and lessens the chance of repair failure.109,110
Loss of the A3 pulley alone has few consequences as well,
but a lengthy sheath cut adjacent to the A3 pulley, contain­
ing the C1 or C2, causes tendon bowstringing.107 Therefore,
significant loss of sheath should be avoided to maintain
tendon function; however, loss of a small portion (<2 cm in
length) of the sheath–pulley, even including a part of the most
critically located A2 pulley, has no substantial mechanical
consequence.
Flexor tendons in the digits glide in a fairly resistance-
free synovial environment. Resistance to tendon motion is
increased when the tendons are injured and repaired. The
following create resistance to tendon gliding: (1) rough tendon
gliding surface; (2) biological reactions of the wound, e.g.,
subcutaneous and tendon edema; (3) friction caused by
Fig. 9.8  The forces acting on the tendon are different when the tendon is subjected
to linear pulling (A) or a curvilinear tension (B,C). (A) The tendon subjected to
linear pulling is loaded by only a linear pulling force. (B,C) The tendon subjected
to a curvilinear tension is loaded by both linear and bending forces. The repaired
tendon fails more easily while being linearly pulled and bent. From (B) to (C), as
the curvature of the gliding path increases, the bending force on the tendon is
increased (F2 > F1). Under greater gliding curvature, the tendon fails with a smaller
linear pulling force. From (B) to (C), as the finger flexes progressively, the tendon
fails with an increasingly smaller linear tension. (C) The tendon is particularly prone
to fail when the finger approaches full flexion. The tendon is easier to disrupt in (C)
when gliding over joints (1′ and 2′) with greater curvature than in (B) with smaller
curvature.
F
F’
2
2’
1
1’
F1
F2
F’
F
F’
A
C
B

195
Treatment/surgical techniques
fingers (10–15%) are missing an FDS tendon. These patients
have limited or no PIP flexion of the little finger during testing.
Weakness during resisted finger flexion indicates a possible
partial tendon cut. To test the FPL tendon, the thumb MCP
joint is stabilized in neutral position. The patient is asked to
flex the IP joint. Loss of active flexion at the joint indicates
complete severance of the FPL tendon.
Nerve and vascular function should be assessed routinely,
because accompanying injuries in the neurovascular bundles
in one or both sides of the fingers or median and ulnar nerves
at carpal tunnel or distal forearm are common. Loss of sensa­
tion in the finger pulps or loss of function of some intrinsic
muscles in the hand are indicative of such accompanying
injuries; treatment of neurovascular injuries must be included
when planning surgical strategies. If fingers or hands are
found to be hypovascular or avascular due to vascular lacera­
tions, vascular anastomosis should be a surgical emergency.
Otherwise, after wound debridement, either the lacerated
flexor tendons can be repaired (when experienced surgeons
are readily available) or the skin can be closed to allow
for delayed primary repairs within days by experienced
surgeons.
Radiographs should always be taken. Associated fractures
are not infrequent and require treatment. Computed tomog­
raphy (CT) scan or magnetic resonance imaging (MRI) are
usually not necessary to diagnose open tendon injuries.
However, for diagnosis of closed tendon ruptures or suspected
ruptures of the primary end-to-end surgical repair, these tools
are of particular value. MRI should be utilized if there is a
suspicion of closed tendon rupture. Ultrasonographic exami­
nation may also reveal rupture of the tendons.
Treatment/surgical techniques
Primary and delayed primary repairs
Whenever possible, acutely lacerated flexor tendons in the
hand and forearm should be treated primarily or at the
delayed primary stage. Primary tendon repair is the end-to-
end repair performed immediately after wound cleaning and
debridement, usually within 24 hours after trauma. Delayed
primary repair is defined as the repair performed within 3 or
even 4 weeks after tendon lacerations. No clinical investiga­
tions actually validated the best time for primary repair. The
ideal situation is that of a patient with digital flexor tendon
lacerations brought into the clinic soon after injury; surgery
begins within a few hours, and an experienced surgeon is
readily available. The tendon injured in critical areas (such as
zone 2) should not be repaired by an inexperienced surgeon.
Rather, the tendon repair can be delayed until an experienced
surgeon is available. My preferred period of deliberate delay
is 4–7 days, when the risk of infection can be properly
addressed and edema has reduced substantially. Delay of the
repair beyond 3–4 weeks may cause myostatic shortening of
the muscle–tendon unit; for these late cases, lengthening the
tendon within the muscles in the forearm can ease the tension
(Fig. 9.11).
Rupture of the repaired flexor tendons after surgery can be
re-repaired if the rupture occurs within a few weeks up to a
month after surgery; secondary tendon grafts may be the only
choice for ruptured cases in the presence of obvious retraction
Fig. 9.9  Examination of flexor digitorum profundus (FDP) tendon continuity and
function. When the proximal interphalangeal joint flexion is blocked, flexion of the
distal interphalangeal joint indicates continuity and function of the FDP tendon.
Fig. 9.10  Examination of flexor digitorum superficialis (FDS) tendon continuity and
function. If the patient is unable to flex the proximal interphalangeal joint of the
examined finger while flexion of the other fingers is blocked, this indicates loss of
function of the FDS tendon. Complete flexion of the proximal interphalangeal joint
indicates function and continuity of the FDS tendon.

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CHAPTER 9 • Flexor tendon injuries and reconstruction
Surgical techniques
The hand and arm are scrubbed and draped. The wounds
should be thoroughly debrided, devitalized tissues excised,
and the wounds washed with antibiotic solution. Position of
the fingers or hand is determined by levels of cuts in the
tendons in relation to their superficial tissues. The hand is
usually held by an assistant, so that it can be adjusted during
surgery. Loupe magnification is advised for surgery. The
tendons are exposed through zigzag skin incisions on the
volar side of the fingers, e.g., Bruner’s incision, or a lateral
incision. When the wounds are in the palm or forearm, inci­
sion by extending the opening of wounds is often necessary
(Fig. 9.12).
of the tendon end or extensive scarring in the intact FDS
tendon when the FDP tendon ruptures.
Indications and contraindications
Primary or delayed primary end-to-end tendon repairs are
indicated mainly in clean-cut tendon injuries with limited
damage to peritendinous tissues. Neurovascular injury is not
a contraindication for primary repairs. Loss of soft-tissue
coverage over the tendon and the presence of fractures are
borderline indications. Local defects in skin and subcutaneous
tissues can be covered by flap transfer. A simple fracture
limited to the phalangeal or metacarpal shaft can be securely
fixed with screws, wires, or intramedullarly placed headless
screws, and then tendons can be repaired. However, serious
crush injuries, severe wound contamination, loss of extensive
soft tissues, or extensive destruction of pulleys and tendon
structures are contraindications for primary tendon repairs.
Severe injuries to multiple joint components and fractures
involving bones at different levels or not yielding stable
internal fixation are contraindications for primary tendon
repairs (Box 9.2).
Anesthesia
Brachial plexus block is usually sufficient; general anesthesia
can also be used when associated injuries are severe. A
tourniquet is placed on the upper arm. Nevertheless, local
anesthesia without tourniquet with the patient being
wide awake during entire surgery can be more beneficial,
called “wide-awake” flexor tendon repair as advocated by
Lalonde.123,124 This approach allows the patient to actively flex
and extend the operated digits, enabling the surgeons to
confirm that the motion is smooth, does not lead to gapping
in the repair site, and the repair strength is sufficient for early
active motion on the operating table. The anesthetic mixture
of 1% lidocaine with 1 : 100 000 epinephrine is given in the
surgical waiting room 20 to 30 minutes before making surgical
incisions (Box 9.3). Epinephrine acts to stop bleeding from
capillaries and produces maximal capillary constriction about
25 minutes after infiltration to the surgical field.
Fig. 9.11  A decision-making flow chart of primary and delayed primary flexor
tendon repairs.
In making a decision of primary repair, consider:
• General conditions of the patient
• Availability of an experienced surgeon
Perform delayed primary repair after
wound infection controlled, edema
subsided and an experienced
surgeon available
Delayed repair with
difficulty, may need to
release muscle tension
Primary
repair
< 1 day
Delayed primary repair
3 weeks
1 month
Tendon
trauma
Day 0
Ideal within 2–3 weeks, possible at 1 month or even later
BOX 9.2  Primary flexor tendon repairs
Indications
1. Clean-cut tendon injuries
2. Tendon cut with limited peritendinous damage, no defects in
soft-tissue coverage
3. Regional loss of soft-tissue coverage or fractures of phalangeal
shafts are borderline indications
4. Within several days or at most 3 or 4 weeks after tendon
laceration
Contraindications
1. Severe wound contamination
2. Bony injuries involving multiple joint components or extensive
soft-tissue loss
3. Destruction of a series of annular pulleys and lengthy tendon
defects
4. Experienced surgeons are not available
BOX 9.3  How to perform local anesthesia for a wide-awake repair
1. Primary or delayed primary repair of the flexor tendons can be
performed under local anesthesia, without tourniquet, while the
patient is wide awake during entire operation.
2. For the repair in zones 1–3, the method of local anesthesia is to
inject 1% lidocaine premixed with 1 : 100 000 epinephrine. The
surgeon should prepare 10 ml of such an anesthetic for each
finger with tendon repair. The local anesthetic is injected
20–30 min before beginning the surgical repair.
3. For zone 1 and 2 injuries, the point of first injection is at the
midpalm level, just proximal to the MCP joint; a total of 5 ml of
anesthetic is injected. The needle should be perpendicular to
the skin to minimize pain, and injection is into the subcutaneous
tissue.
4. After waiting 5–10 minutes, the second injection (2 ml) is given
to the middle part of the proximal phalanx at the volar midline.
Immediately after that, the third and fourth injections (2 ml and
1 ml, respectively) are administrated to the middle parts of the
middle and distal phalanx along the palmar midline.
5. 15 minutes after completing the above four injections, surgery
can begin.
6. For repair in the forearm (zone 5), 20–50 ml of 1% lidocaine with
1 : 200 000 epinephrine is injected to the multiple sites where
surgical incisions will be made 15 minutes before surgery.

197
Treatment/surgical techniques
Zone 1 injuries
In this area, only the FDP tendon is located. When the tendon
laceration is in the distal part of this zone (zone 1A and 1B),
because the vincula connects to the proximal tendon to
prevent retraction, both the proximal and distal ends can be
easily found not far from the skin wound in many cases.
When cut in zone 1C and some distal tendon cuts, the tendon
may retract more proximally. Often it is necessary to make an
incision to find the retracted proximal stump. Using a forceps
the surgeon can feed the proximal tendon forward from
the incision in the palm, bit by bit, to the distal incision in the
finger (Fig. 9.13). This maneuver does not traumatize the
sheath tunnel or the end of the proximal tendon. Then, a
25-gauge needle is inserted at the base or middle of the
finger through the proximal tendon to hold the tendon
temporarily.
For zone 1A injuries, the distal stump is very short. The
proximal tendon end can be sutured with Bunnell or modified
Becker suture with 3-0 polypropylene, and an osteoperiosteal
flap is raised at the base of the distal phalanx (Fig. 9.14). The
suture is led through an oblique drill-hole, brought out
through the nail, and tied over a button above the nail. To
avoid passing the suture through the nail, the proximal
tendons can be sutured to a fish-mouth opening in the distal
tendon stump using reinforced suture repairs or mini-anchors
(see Fig. 9.14).157,158 Another method is to drill a transverse
hole through the distal phalanx. After the tendon stump is
Fig. 9.12  Skin incisions utilized to approach the tendons in the digits and palm.
Fig. 9.13  A separate incision in the distal palm is often necessary to find retracted
flexor digitorum profundus tendon and advance it distally. (A) An incision in the
distal palm to find the proximal stump. (B) Feeding the retracted proximal tendon
forward to the surgical field in zone 1 bit by bit using forceps without traumatizing
the tendon stump, which the author often uses. (C) A needle was inserted
transversely through the sheath and proximal tendon to temporarily fix the proximal
tendon to ease tension during repair.
A
B
C

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CHAPTER 9 • Flexor tendon injuries and reconstruction
Fig. 9.14  Methods of making a tendon-to-bone junction in zone 1. (A) A conventional method to
anchor the flexor digitorum profundus (FDP) tendon to the bone by pull-out sutures through the nail
and tied over a button. Alternative ways to anchor the distal tendon stump to the bone by:
(B) directly suturing the stump to residual FDP tendon; (C) looping the tendon through the bone;
(D) pull-out suture over the fingertip; (E) mini-anchors; (F) looping the sutures through a
transverse hole in the bone; and (G) a set of 10 or more strands of robust repairs from the proximal
stump to the distal stump, nearby periosteum, and distal insertion site of the volar plate of the
distal interphalangeal joint.
A
B
C
D
E
F
Mini anchors
Sutures
FDP tendon
Button
G

199
Treatment/surgical techniques
Fig. 9.15  A tendon-to-bone junction made through splitting the short distal stump
and reinforced suture repair to the proximal stump or a graft using a 4-0 suture.
Fig. 9.16  A case of direct suture repair of the proximal stump to the short distal stump with a set of robust 12-strand core sutures made with 4-0 suture. (A) In making the
first set of repairs: two-strand Kessler, the first bit is in the proximal stump; (B) the suture was placed to both stumps; (C) after completion of all 12-strand core sutures
the repair consists of a Kessler repair in the tendon and a few two-strand repairs with rectangle configuration of different lengths extending to other tissues as shown in (D);
and (D) drawing depicting this robust direct attachment. The sutures placed after the first Kessler were extended to the periosteum and the other adjacent tissues to help
anchor the sutures.
A
B
C
D
sutured, the suture is led through the hole and tied to the
other end, through an open approach or percutaneously.159
Other methods include: (1) reinforced suture repair of the
proximal FDP tendon stump to the distal stump with 4-0 or
3-0 sutures, after the distal stump is split along the midline
and the proximal stump is placed between the two slips of the
split distal stump;160 and (2) an extremely robust end-to-end
repair, with 10 or 12 strands with 4-0 sutures to connect the
proximal tendon to the distal stump, periosteum of the distal
phalanx, and the distal anchoring part of the volar plate of the
DIP joint (see Fig. 9.14). The author uses both methods (Figs.
9.15 & 9.16) and finds that they have sufficient strength.
Injuries in zones 1B and 1C usually create tendon stumps
of sufficient lengths for a more common end-to-end repair,
which can be treated by methods similar to treatment in zone

200
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CHAPTER 9 • Flexor tendon injuries and reconstruction
2. Core tendon sutures, such as the cruciate, modified Becker,
Strickland, double Kessler repairs, six-strand triple Kessler, or
M-Tang, can be placed to the proximal end through a window
opening in the proximal sheath. The proximal end is brought
underneath the intact sheath between the wound and the
proximal opening to approximate the distal end.
Zone 2 injuries (Videos 9.1–9.5 )
Tendon injuries in this area are often exposed through a
Bruner skin incision and a window opening in the synovial
sheath, a release, or local excision of a short part of the annular
pulleys. If the tendon ends have not retracted far proximally,
flexion of the MCP or PIP joint can effectively bring the proxi­
mal end into sight. Sometimes the proximal tendon end is
found retracted even to the middle of the palm. In this
instance, an additional incision of 1–1.5 cm is made in the
distal or middle of the palm around the MCP joint level to
expose the tendons. By loosely suturing the proximal tendon
end to a catheter, the proximal tendon end is then pulled
distally within the synovial sheath, or the proximal tendon is
advanced underneath the intact sheath tunnel by alternately
feeding the tendon with two pairs of forceps from the palm
incision (see Fig. 9.13). The end is brought out of the distal
opening in the sheath to approximate the distal end. While
the finger is held in slight flexion, a 25-gauge needle is then
inserted at the base of the finger through the proximal tendon
to hold the tendon temporarily and to release the tension at
the surgical suture site.
During surgery, tendons should be handled atraumatically,
and ragged tendon tissue at the cut ends should be removed
with a scalpel or fine scissors. Stronger suture materials are
preferred; 3-0 or 4-0 sutures (nylon or coated nylon) are
common choices. Basic requirements of a tendon repair are:
(1) sufficient strength; (2) smooth tendon gliding surface, with
minimal suture (and knot) exposure; (3) no gapping of the
repair site under tension; and (4) ease to perform.
Surgical suture techniques used vary among surgeons.
Some of core suture methods are shown in Fig. 9.17. The
modified Kessler and cruciate techniques are further detailed
in Fig. 9.18. The Bunnell method is no longer popular for
end-to-end repair. The two-strand modified Kessler method
and Tsuge method are among the most widely used over the
past 40 years. In the last 25 years, a number of multistrand
repair techniques have emerged,14–19,65–69 which include four-
strand repairs such as cruciate, modified Savage, Strickland,
Fig. 9.17  Summary of some methods used to make core sutures in flexor tendon repairs.
B
A
D
C
F
E
H
G
J
I
Bunnell
Tsuge
Cruciate
4-strand Savage
Tang or 6-strand Tsuge
Modified Kessler
Double Kessler
Indiana or 4-strand Strickland
Modified Becker
Modified Savage

201
Treatment/surgical techniques
Fig. 9.18  Two common techniques in flexor tendon repairs. (A) Modified Kessler method. (B) Cruciate method.
A
B
i
ii
iii
i
ii
iii
and double Kessler; six-strand repairs such as Savage, Lim–
Tsai, Tang, and M-Tang; and eight-strand Winters–Gelberman
methods. Most surgeons now prefer a multistrand repair. The
author uses multistrand methods, typically a six-strand repair
method, in repairing lacerated FDP tendons in zone 2.
In the author’s practice, the double Tsuge method or six-
strand methods have been used in the past 25 years. In the
past 15 years, the author and colleagues have used modifica­
tions of the original methods to repair tendons using fewer
looped lines and knots, but maintaining suture strands and
repair strength across the repair site identical to those of the
original methods (Fig. 9.19). These methods are relatively
easy, and surgical repair strength is very reliable (Figs.
9.20–9.26).
Surgeons use many variants of multistrand repairs in an
FDP tendon repair: a variant of the Strickland method is used
at Stanford University, a locking cruciate repair at the Hospital
for Special Surgery in New York (Fig. 9.27), and an eight-
strand core suture is used at Washington University in St.
Louis, Missouri. The six-strand Lim–Tsai method is used at
the University of Bern, Switzerland and a six-strand Tang
method at Broomfield Hospital in Chelmsford, England. The
author has also used an asymmetric six-strand Kessler repair,
a method of three groups of two-strand Kessler repair made
with different purchase lengths in two tendon stumps to
better resist gapping (see Fig. 9.27). For FDS tendon cut proxi­
mal to bifurcation, I also used a four-strand repair carrying a
looped suture or two separate suture lines (see Fig. 9.27).72 To
make a successful repair, surgeons should follow some uni­
versal principles, such as ensuring strong core suture repair,
sufficient suture purchase, secure anchor of the suture to the
tendon and knot security, and creating tighter tension over the
repair site. Once such principles are followed, suture configu­
ration itself is not vital. The multistrand methods described
– preferred in different centers – may be likewise reliable.
Epitendinous stitches smooth the approximation of the
tendon ends and resist gapping during tendon movement.
Simple running peripheral, locking running peripheral, cross-
stitch peripheral, and Halsted horizontal mattress sutures are
among those most often used, with the first two more popular
(Fig. 9.28). Some surgeons prefer “deep-bite” peripheral
stitches to add strength to repairs.156 An epitendinous suture
is usually added after completion of core sutures, but it can
also be added first.161 Peripheral stitches can be unnecessary
given a strong multistrand core suture.25 Clinically, peripheral
repairs vary from complex stitches to none. The author’s
preference is to use a simple running peripheral suture with
6-0 nylon after completion of a four- or six-strand core suture
repair.
Technically, to make an optimal surgical repair, the length
of core suture purchase in each tendon end should be at least
7 mm to 1.0 cm. Surgical repair strength decreases as the
length of the suture purchase decreases (Fig. 9.29). In addi­
tion, a certain tension across the repair site is beneficial to
resist gapping. In the author’s experience, a certain tension
(that results in about 10% shortening of the encompassed
tendon, when the proximal tendon is temporarily fixed during
surgery) appears beneficial, because a small amount of base­
line tension in the repair would counteract the tension of the
locomotor system during resting or active motion. When
locking suture-junction in the tendon is incorporated in the
core sutures, the locking circles of the suture in the tendon
should be of a sufficient diameter (approximately 2 mm).
After completing the repair, the cut tendon ends should align
well, and no gapping between the tendon ends should be
observed (Box 9.4).
In the past 15 years, novel repair concepts have emerged
and novel materials have been used. For example, of potential
clinical merit are techniques involving a single passage of
the needle carrying double or even triple strands into the
tendon;69,155,161–163 FiberWire also offers a strong suture material
for tendon repairs.95,155 These methods are effective in enhanc­
ing strength with a minimal suture passage in the tendon.
Closure of the synovial sheath is no longer considered
essential for tendon repairs after hot debate in the 1980s and
early 1990s.164–171 Closure may be attempted in clean-cut injury
when sheath defects or abrasions are absent. It is now agreed
that avoiding compression or constriction to the edematous

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CHAPTER 9 • Flexor tendon injuries and reconstruction
tendons by the sheath or annular pulleys after surgery is very
important to tendon healing. With major pulleys and a major­
ity of the sheath intact, leaving a part of the synovial sheath
open has no significant adverse effect on tendon function and
healing. On the other hand, incision of one single annular
pulley (A1, A3, or A4) or a critical part (up to two-thirds of its
length) of the A2 pulley does not significantly affect tendon
gliding when all other pulleys or the synovial sheath are
intact. Such a release can in fact be beneficial to tendon healing
and gliding: as healing responses and adhesions arise, it
releases constrictions on edematous tendons.
Clinically, the A4 or A2 pulley sometimes constitutes an
obstacle for the edematous tendon to glide through, which
Fig. 9.19  The technique for making a six-strand M-Tang tendon repair. Two
separated looped sutures are used to make an M-shaped repair within the tendon.
(A–C) A U-shaped four-strand repair is completed, which can be used alone for
tendon repair. (D,E) An additional looped repair is added at the center, to complete
the six-strand repair. In tendon cross-sections, three suture groups are placed at
points of a triangle to avoid interference to the dorsal center of the tendon where
the vascular networks converge. The dorsolateral sutures may act as tension bands
to resist gapping of the tendon.
A
B
C
D
E
Fig. 9.20  A case with complete laceration of the flexor digitorum profundus tendon
and partial flexor digitorum superficialis tendon laceration in zone 2B. The surgery
was performed 10 days after injury. The wound was exposed through a Bruner
incision, and the distal half of the A2 pulley was incised through the volar midline.
Intact part
Vented part
Fig. 9.21  The lacerated flexor digitorum profundus tendon was found through a
separate incision in the palm and was led underneath the sheath and pulleys to the
operation field distal to the A2 pulley, to approximate the distal stump.
Fig. 9.22  Completion of inserting a four-strand repair using one looped suture
line.

203
Treatment/surgical techniques
Fig. 9.23  Completion of the six-strand M-Tang repair.
Fig. 9.24  Addition of a simple running peripheral repair.
Fig. 9.25  Follow-up at 10 months after surgery, full flexion of the repaired finger,
without tendon bowstringing.
Fig. 9.26  Full extension of the repaired finger.
Fig. 9.27  Other designs of four-, six-, eight-, or ten-strand repairs used in different
centers. (A) A variant of the Strickland repair (Stanford University, USA). (B) An
eight-strand repair (Washington University in St. Louis, USA). (C) A six-strand
asymmetric Kessler repair (Nantong University, China). (D) A ten-strand repair that
the author use for late direct repairs.
A
B
C
D

204
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CHAPTER 9 • Flexor tendon injuries and reconstruction
Fig. 9.28  Two simple, common methods of peripheral suture. (A) Simple running
peripheral suture. (B) Running locking peripheral suture.
B
A
Simple running peripheral suture
Locking running peripheral suture
Fig. 9.29  Two bad repairs decrease the strength: (A) a repair with short core suture
purchase and (B) a loose repair. Sufficient core suture purchase and a certain
pre-tension favor resisting gapping and decrease the chance of repair failure during
tendon motion after surgery.
B
A
Gapping / disruption
Solution : Maintain core suture purchase
>7–10 mm
< 4 mm
Tension
Gapping
Loose repair
Solution : Repair with a certain
light tension
Tension
BOX 9.4  Recommended surgical tendon repair requirements
• More than 2 strands as the core repair – four- or six-strands
recommended.
• Certain tension across the repair site – 10% shortening of
tendon segment after repair.
• Core suture purchase: 7–10 cm.
• Locking tendon-suture junctions in core suture.
• Diameter of the locks: 2 mm or over.
• Suture calibers: 3-0 or 4-0 for core suture.
• A variety of nylon sutures, or a FiberWire suture.
• A simple running or locking peripheral suture.
• Minimal separate stitches of peripheral suture if core repair is
extremely strong.
• Avoid extensive exposure of sutures over the tendon surface.
may cause repair rupture during tendon motion exercise. The
perceived need for complete preservation of the A4 and A2
pulleys during primary repairs is “borrowed” from the
surgery pertaining to secondary tendon reconstructions, and
does not hold true when the tendons are cut through a single
wound and other sheaths or pulleys are intact. Contrary to
the practice of 10 or 20 years ago, releasing the A4 pulley
entirely and releasing a part of the A2 have become accepted
clinical practice in recent years.19,23,150,172,173 In the author’s
clinic, when the repaired FDP tendons are found tightly
entrapped by the A4 pulley after testing during surgery, the
A4 pulley is completely released (Figs. 9.30–9.32) (Box 9.5). A
Fig. 9.30  The constricting A4 pulley sometimes presents an obstacle for the
passage of the flexor digitorum profundus tendon.
Fig. 9.31  The A4 pulley and a part of its adjacent sheath were vented to allow
tendon passage in this patient. Other parts of the sheath were not violated. In this
case, the flexor digitorum profundus tendon was repaired with a six-strand original
Tang repair with three groups of looped sutures.

205
Treatment/surgical techniques
Over the years, release of the pulleys has been achieved
differently: (1) incision of the entire or a critical part of the
major pulley;19,22,23,150 (2) excision of a part of the major pulley;19
(3) Omega pulley plasty;174 and (4) sheath enlargement
plasty.175,176 My current pulley release is a simple procedure:
incising the A4 or a portion of the A2 pulley, or partially
excising the A2 pulley, while obviating complicated sheath- or
pulley-plasty surgeries.
Whether or how to repair the FDS tendon when both flexor
tendons are injured is a subject of diverse opinions, particu­
larly in the areas covered by the A2 pulley or distal to it. A
few reports have discussed it specifically.21,177,178 Repair of one
part of the A2 pulley, either proximal or distal (about one-half
to two-thirds length of the A2 pulley; see Figs. 9.20–9.24), is
cut when both the FDS and FDP tendons are repaired in the
area of or distal to the A2 pulley. When the repair is consider­
ably delayed (3 weeks after injury), the A2 pulley usually
collapses or is even embedded within scars. A portion of the
A2 pulley is excised to shorten this pulley (Figs. 9.33–9.37).
The release usually needs to include a part of adjacent
synovial sheath. The total length of the sheath–pulley release
is about 2 cm in adults, which amply decompresses tendon
gliding, but does not lead to functional disturbance. The areas
of the release are shown in Fig. 9.38.
Fig. 9.32  A case of delayed primary repair. (A) An intact A4 pulley was seen. (B) The
A4 pulley was cut open entirely to allow tendon repair. The flexor digitorum profundus
tendon was repaired with a six-strand asymmetric Kessler repair (see Fig. 9.27C).
(C) Methods of venting a pulley: midline cut, lateral cut, or shortening.
A
B
Shortening
Midline incision
Lateral incision
C

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CHAPTER 9 • Flexor tendon injuries and reconstruction
BOX 9.5  When and how to vent the A4 pulley for tendon repair
1. The A4 pulley is located at the middle part of the middle
phalanx, about 5 mm long.
2. The A4 pulley is rigid, constrictive, and narrow.
3. When this pulley prevents smooth passage of the retracted FDP
tendon underneath, or when the pulley is found to prevent
smooth gliding of the repaired FDP tendon during digital
extension–flexion test (see Box 9.6 for method detail), this pulley
can be entirely vented after the surgeon confirms that all other
annular pulleys are intact.
4. The A3 pulley should usually be preserved. In the rare case
when the A3 pulley has to be vented, any synovial sheath
proximal to the A3 should be entirely preserved.
5. The entire length of the sheath–pulley venting should be less
than 1.5–2 cm over the middle phalanx area.
6. The method of venting is (1) direct cut along the palmar midline
of the pulley, or (2) direct cut along the lateral side of the pulley,
or (3) resection of this pulley if it has been embedded inside
adhesions and fibrosis.
Fig. 9.33  A case of ruptured primary repair referred to the author. Direct repair of
the ruptured flexor digitorum profundus tendon was performed 3 weeks after the
first tendon repair. The flexor tendons and the A2 pulley were found embedded
within scars.
Fig. 9.34  The A2 pulley was partially excised and the intact part of the A2 pulley
was released from the scar. The ragged tendon ends were trimmed to fresh tendon
surfaces.
Fig. 9.35  The proximal tendon stump was passed underneath the preserved
portion of the A2 pulley. The tendon was repaired with the six-strand M-Tang
technique.
Fig. 9.36  Follow-up 6 months after surgery. Full flexion of the finger, with no loss
of digital flexion and no tendon bowstringing.
slip of the FDS is also feasible.100,108 In the area of the A2 pulley
(zone 2C), the author prefers to locally excise the FDS in cases
with severe peritendinous injuries, when the tendons appear
edematous, and in cases with delayed primary repairs. In
performing the delayed repair, the author finds it almost
impossible to repair the FDS tendon in zone 2C, because some
degree of collapse or narrowing of the A2 pulley is inevitable,
and the tendons are often edematous. In zone 2B, where the
FDS tendon is bifurcated into two slips, the author uses two
Tsuge repairs separately in each tendon slip; when the lacera­
tion is close to the insertion, the tendon slips are anchored to
the phalanx. Treatment of the FDS tendon in zone 2D is
straightforward, similar to the FDP tendon except that the
FDS is flatter and four or fewer strands are used.

207
Treatment/surgical techniques
Fig. 9.37  Full extension of the fingers, without extension deficits of the finger
joints.
Fig. 9.38  Drawings depicting the length and areas of release of the pulley–sheath complex to decompress the repaired tendons, without bowstringing or loss of tendon
function. (A) Release of the entire A4 pulley when the flexor digitorum profundus tendon has been cut around the A4 pulley and the tendon cannot pass easily beneath this
pulley during surgery. (B) Release of a part of the sheath distal to the A2 pulley and the distal half of the A2 pulley, when the tendons are cut a little distal to the A2 pulley.
(C) Release of a short part of the sheath distal to the A2 pulley and the distal two-thirds of the A2 pulley when repairing tendons cut at the edge of, or in the distal part of,
the A2 pulley. (D) Release of the proximal two-thirds of the A2 pulley when repairing a cut in the middle, or proximal part of, the A2 pulley.
A1
A2
C1
A3
C2
A4
C3
A5
Tendon laceration
A1
A2
C1
A3
C2
A4
C3
A5
Sheath–pulley release
Tendon laceration
Sheath–pulley release
Tendon laceration
Sheath–pulley release
Tendon laceration
Sheath–pulley release
A
B
C
D
In deciding surgical options relating to both the FDS and
the pulleys, the author generally seeks to appropriately
decrease the gliding contents (by not repairing or excising the
FDS tendon) or enlarge the sheath (when both tendons are
repaired primarily or only the FDP tendon is repaired at the
delayed stage). The underlying idea is that the fibro-osseous
digital flexor sheath tunnel is comparable to a tight fascia
compartment of extremities; the edematous and healing
tendons are compromised easily. Release of compression of
the tendon to avoid overloading it during motion can be more
vital to the success of treatment than providing it with suffi­
cient surgical strength.
Surgical options currently advised to deal with the tendons
and pulleys in the most complex areas of finger flexor tendons
are summarized in Table 9.1.
Once surgeons have completed surgical repair of the
tendon, and vented the pulleys in case of need, an intra­
operative test – “digital extension–flexion test” – should be
performed before closure of surgical incisions.149 Detailed in
Box 9.6, this test consists of three parts: full extension of the
operated digit, flexion of the digit from full extension to
flexion, and finally maximal digital flexion (Fig. 9.39). If the
repair fails this test, the repair should be either redone or
enhanced, or the annular pulley proximal to the repair vented
further, depending on the circumstance. If the repair is a wide-
awake surgery, the patient should move the digit actively on

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CHAPTER 9 • Flexor tendon injuries and reconstruction
by lacerations to the median nerve. The transverse carpal
ligament may be partly or entirely opened to facilitate repairs
and left partly open after tendon repairs. Zone 5 tendon
injuries usually present as multiple tendon lacerations with
neurovascular injuries. A wrist with transection of a major­
ity of tendons, vessels, and nerves (at least 10 out of 15
of these structures, excluding palmaris longus) is called a
“spaghetti” wrist.179–183 A “spaghetti” wrist was reported to
have an adverse effect on the recovery of the independent FDS
action but not on the recovery of digital range of motion.183
In zone 5, repair of the FDS tendon is preferred, and early
postoperative tendon motion is advised,183–185 which favors
independent movement of the superficialis. However, the
FDS tendon to the little finger may be absent or too slender
to repair.
FPL injuries
Repair of the injured FPL tendon in the thumb usually follows
the same principles and methods of repairs of the FDP tendon
in fingers. Multistrand repairs are advised, and one or two
pulleys can be vented to free tendon motion. Reports have
shown that conventional two-strand repairs have a risk of
rupture as high as 17%.25,172 In a report from David Elliot’s
hand center, Giesen et al.25 reported no ruptures and good
function after use of a six-strand Tang method without
peripheral sutures in repairing 50 FPL tendons. In this case
series, which reported the best outcomes of FPL tendon repairs
thus far, the pulleys were vented and the sheath was not
closed. The authors found that this six-strand repair was safe
for early active mobilization and easier to perform than
Kessler core sutures and elaborate Silfverskiöld sutures.
In repairing the FPL tendon, the proximal cut end of the
tendon frequently retracts into the thenar muscles. This end
can be retrieved with the techniques described for retracted
FDS and FDP tendons (Figs. 9.41 & 9.42). If the proximal
stump of the FPL tendon has retracted proximal to the thenar
Table 9.1  Summary of mechanical basis and surgical options advised to deal with the flexor digitorum superficialis (FDS) tendon and
pulleys in zone 2 of the finger
Investigations
Area of FDS insertion
Distal to A2 pulley
Beneath A2 pulley
Proximal to A2 pulley
(2A)
(2B)
(2C)
(2D)
Anatomic
FDS tendon
Insertion
2 slips, dorsal to FDP,
with vincula
Bifurcation
One single band, flattened
palmar to FDP
Pulleys
A4, C2, narrow
A3, C1
A2, narrow
A1, PA
Biomechanical
FDS tendon
No gliding
Not constricting FDP
Constricting FDP, as a moving
and second “pulley”
Little constriction
Pulleys
A4 release is feasible112
May incise one pulley107
Partial release is feasible22,111,112
Clinical options
FDS tendon
Repair174,214
Resection or do not repair21,23,150
Resect one slip101
Repair both tendons when
possible
Pulleys
A4 venting19,23,172
Partial release19,23,150,172
Pulley shortening or plasty100,175
FDP, Flexor digitorum profundus; PA, palmar aponeurosis.
BOX 9.6  When and how to perform an extension–flexion test
• This test should be performed after any kind of primary repair of
flexor tendons in the digital and palm area, to make sure the
repair is strong and that tendon gliding is smooth before closure
of surgical incisions.
• There are three parts to this test. Part 1: Full passive extension
of the digit that has undergone surgery by the operator, to
confirm that the tendon repair site has no gapping.
• Part 2: From the fully extended position, the operated digit is
passively flexed to moderate degrees, to confirm that the
tendon and the repair site can glide smoothly.
• Part 3: Further pushing the digit to full or almost full flexion, to
confirm that the tendon repair site does not impinge against
rigid annular pulleys.
• If tendon gapping is found with digital extension, the repair
should be reinforced, or if annular pulleys block tendon gliding
with digital flexion, the pulleys should be vented, according to
guidelines for treatment of pulleys.
• The results of the above tests are included in the operative
notes and the therapists are informed.
the operating table, which offers the most objective measure
of quality of the repair (Fig. 9.40). If a repair fails the test
intraoperatively, this poor repair is bound to gapping or dis­
ruption in later early active motion; therefore it should be
revised before leaving the operating table.
Zone 3, 4, and 5 injuries
The repair techniques for injured flexor tendons proximal to
zone 2 are almost identical to those used in zone 2. These zones
have a better prognosis because of richer vascularity around
the tendon and lack of constricting pulleys over the tendons.
Adhesions in these areas are less likely to impede tendon
motion. Zone 4 tendon injuries are frequently accompanied

209
Treatment/surgical techniques
of active digital motion between the two methods. Elhassan
et al.189 reported that early postoperative motion and immobi­
lization did not affect outcomes in children aged 2–14 years
with injuries in zones 1 and 2.
Partial tendon lacerations
Laceration through less than 60% of the diameter of the
tendon does not necessitate a repair by core sutures. An
increased risk of triggering, entrapment, or ruptures is associ­
ated with partial laceration over 60%.191–195 For lacerations less
than 60%, the tendon wound can be trimmed to lessen the
chance of entrapment by pulley edges and friction against the
sheath. Alternatively, the cut portion of the tendon can be
repaired with epitendinous stitches to smooth the tendon
surface and to strengthen the tendon. Laceration of 60–80%
requires at least an epitendinous repair196–199 and is better
repaired using a two-strand core suture through the cut
portion. Laceration of 80–90% is treated identically to a com­
plete laceration.
Closed rupture of the flexor tendons and pulleys
Traumatic FDP tendon avulsion from the tendon–bone junc­
tion accounts for a major portion of closed rupture cases.200–203
The injury mechanism is hyperextension of the DIP joint,
which subjects the FDP tendon to excessive load. The tendon
disrupts at its insertion to the distal phalanx. Athletic injuries
can lead to this type of injury. In football, wrestling, or rugby,
when one player grabs another’s jersey, a finger gets caught
and pulled, resulting in disruption of flexor tendons. This
injury (“jersey finger”) is seen most commonly in the ring
finger. Closed tendon ruptures at the wrist can be associated
with fractures in carpal bones.203 Flexor pulleys are prone to
sprains and ruptures during climbing. Rupture of the pulleys
occurs in up to 20% of climbers.204 The A2 pulley of the ring
finger is the most often injured. Closed pulley ruptures are
treated conservatively or by surgical reconstruction.
Leddy and Packer200 classified close tendon ruptures into
following types:
I.
The FDP tendon is avulsed from the phalanx and
retracts into the palm. The vincula of the FDP tendon
are disrupted. There is no active flexion of the DIP joint.
A tender mass is present in the palm. The tendon
should be reinserted within 7–10 days before the sheath
collapses, which may prevent advancing the tendon
distally. Muscle contracture may also prevent tendon
advancement.
II. The FDP tendon retracts to the level of the PIP joint.
This is the most common type. The sheath is not
compromised, and muscle contracture does not
develop easily. Repair may be attempted 1 month after
injury.
III. A large bone fragment is attached to the FDP tendon.
This bone fragment frequently prevents the tendon from
retraction proximal to the A4 pulley. Bony fixation using
a K-wire or a screw usually suffices.
IV. The FDP tendon avulses from the bony fragment. This
type was added by Smith.200 The avulsed tendon retracts
beyond the middle phalanx and even into the palm. In
treating type IV injuries, the bony fragment is attached
into the distal phalanx first; then the avulsed tendon is
muscles, a separate incision in the forearm is required to
locate the stump. The FPL stump usually lies deep to the FCR
tendon and the radial artery.
Injuries in children
Flexor tendon repairs in children have a better prognosis than
those in adults.186–190 As children may be less compliant with
instructions to limit movement, the repaired digits are usually
immobilized for 3–3.5 weeks after surgery. Either a two-strand
or a four-strand repair can be used. In practice, many surgeons
use a two-strand repair and achieve good return of function.
The outcomes appear unaffected by whether a two- or four-
strand repair is used or whether the tendon is moved or
immobilized early after surgery.188,189 Navali and Rouhani188
reported that both a two-strand and four-strand repair
achieved good functional return, with no difference in range
Fig. 9.39  Extension–flexion test of the repaired tendon before closure of surgical
incision. (A) Full extension of the digit. (B) Motion from full extension to flexion.
(C) Completing the maximal flexion. In wide-awake surgical settings, the digital
motion is active, providing the best measure of quality of surgical repair.
Confirm pulley does not impinge
on tendon gliding
Confirm smooth gliding on digital flexion
Confirm no gapping
A
B
C

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SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
A
B
C
D
E
F
Fig. 9.40  Primary tendon repair of the tendon in the A2 pulley area (zone 2C) under a wide-awake setting. (A) The first injection of 5 ml of the 1% lidocaine with
1 : 100 000 to the palm 30 minutes before surgery. (B) The second injection was given 15 minutes later, to the proximal part of the digit, followed immediately by injection
to the middle and distal parts of the digit (C,D). (E) A close-up view of making the first anchor of the looped suture to the tendon in the six-strand M-Tang repair. Note that
the site of needle entry is 1 cm away from the cut end and the size of the lock is large. (F) The U-shaped repair with the first looped suture was completed. Two strands of
centrally placed looped sutures was added later to complete the 6-strand core repair.

211
Treatment/surgical techniques
Fig. 9.41  A 9-year-old boy with a complete flexor pollicis longus tendon cut. The retracted proximal tendon end was found and was temporarily fixed with a needle to
accommodate tendon repair (A). The FPL tendon was repaired with the six-strand M-Tang technique (B).
A
B
G
H
I
(D) After completion of the six-strand repair and simple
peripheral suture, the patient actively extended (G) and actively flexed (H) the digit
to check quality of the repair. (I) Pictures taken 5 months later showing full recovery.
Fig. 9.40, cont’d

212
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CHAPTER 9 • Flexor tendon injuries and reconstruction
was applied with the wrist in 20° flexion, the MCP joint in 50°
flexion, and the IP joints were allowed full extension (Fig.
9.43). Within the first 4.5 weeks, the patients performed 10
passive DIP joint extensions with PIP and MCP joint flexions,
and 10 passive PIP joint extensions with MCP and DIP joint
flexions hourly within the splint (see Fig. 9.43).
Strickland and Gettle modified this protocol by adopting a
Duran-like protocol for a four-strand tendon repair,209 later
known as the “Indianapolis method”. This protocol consisted
of two splints, the dorsal-blocking splint (used during periods
of rest and passive motion, with the wrist at 20–30° of flexion,
MCP joints in 50° of flexion, and IP joints in neutral position)
and a tenodesis splint (used when performing place and hold
exercise). The latter hinged wrist splint permitted the wrist
position to be varied between flexion and extension. With the
tenodesis splint, the patient passively flexed the digits while
actively extending the wrist. The patients passively pushed
their fingers into a passive composite fist with the wrist
extended and hold for 5 seconds. The patients relaxed the
wrist and let it descend into flexion. Patients were instructed
to exercise 25 times per waking hour. Four weeks after surgery,
active digital flexion and extension was instituted with the
dorsal blocking splint still on and the tenodesis splint was
discontinued. One week later, active composite fist followed
by active extension of the wrist and digits was added to the
program. When both flexor tendons are repaired in the digital
sheath, differential motion of the two tendons could be prac­
ticed. Shifting the finger postures from straight, hook, and fist
positions generated differential gliding of the two tendons.
Early active motion
In the late 1980s and early 1990s, protocols containing early
active tendon motion components emerged. One requirement
is that the tendon repairs be strong enough to tolerate the
tension during the motion. In 1989, Belfast surgeons devised
an active motion protocol,210 which was later known as
advanced. Postoperatively, the DIP joint is immobilized
for 4–5 weeks, or a gentle motion regime is prescribed.
Early recognition of closed tendon ruptures is of paramount
importance. In the cases of late diagnosis, primary repair is
difficult or even impossible. Chronic cases require free tendon
grafting.
Postoperative care
With the exception of a few instances – such as tendon repairs
in children, adults who are unable to follow through the
protocol, or associated with complex fractures – motion of
repaired tendons should be initiated from the early postsurgi­
cal period. From the 1970s to 1990s, the Kleinert and Duran–
Houser protocols were most popular. In recent years, a variety
of combined passive–active flexion protocols have been
developed, replacing passive flexion protocols. The protocols
have evolved and the methods presently used in many clinics
are combined passive–active digital flexion regimes.
In the 1960s, Kleinert and associates introduced a controlled
active extension–passive flexion protocol, which was a con­
ceptual breakthrough.205 They placed the wrist in palmar
flexion of 30° to 40° and 60–70° MCP joint flexion with a dorsal
protective splint. Rubber bands were attached to the volar
forearm and to the tip of the finger. The patients were allowed
to actively extend the fingers and the fingers were brought
back to flexion passively by the tensed rubber bands. This
traction was found to lead to flexion contractures of the finger,
with the original protocol as well as after a pulley for the
rubber band added at the MCP joint level in 1990s.206,207 There­
fore, the rubber band traction has mostly been abandoned.
Duran–Houser method
This was a controlled passive finger flexion protocol intro­
duced by Duran and Houser in the 1970s.208 A dorsal splint
A
Fig. 9.42  Follow-up 8 months after surgery. (A) Full flexion of the repaired thumb. (B) Full extension of the thumb.
B

213
Postoperative care
A
Duran and Houser passive motion regime
B
C
Fig. 9.43  (A) Duran passive tendon motion protocols. (B) Nantong regime. Passive flexion of the fingers over 20–40 times, followed by partial active digital motion to
one- or two-thirds of the entire arc of finger flexion.
D

214
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CHAPTER 9 • Flexor tendon injuries and reconstruction
“Belfast method”. Postoperatively, a splint is applied from the
elbow to the fingertips with the wrist in mid-flexion, the MCP
joint at slightly less than 90° flexion, and the IP joints straight.
The light dressing is removed from the digits and exercises
commences 48 hours after surgery. Under supervision, the
exercises consist of two passive movements followed by two
active movements and are performed at 2-hour intervals. The
hand is rested in elevation overnight. During the first week,
the PIP joint is actively flexed through about 30° and the DIP
joint through 5–10°. In subsequent weeks, the range of active
motion is gradually increased. The splint is removed by the
6th week and blocking exercises of the IP joints are initiated
when necessary. Variants of the Belfast method have been
reported. In one of the variants, the “Billericay regimen”, the
wrist and the MCP joint are kept in a splint at 30° flexion,
respectively, and the splint is removed by the fifth week. The
patient is instructed to perform 10 repetitions of exercise
hourly.211
Author’s preferred combined passive–active
method (Nantong regimen)
After surgery, the hand is protected in a dorsal thermoplastic
splint, with the wrist at 20–30° flexion, MCP joint at slight
flexion, and the IP joints in extension for the initial 2.5 weeks
(3 weeks or slightly longer when the trauma is severe or
digital edema is remarkable) (see Fig. 9.43).19 The wrist can be
placed at neutral position instead. We do not encourage the
patients to move the finger in the initial postoperative days;
exercise starts at 3–5 days after surgery. The patient is
instructed to perform at least 4–6 sessions of combined
passive–active motion daily across the morning, noon,
evening, and before sleep. More sessions can be implemented
as needed, while hourly exercises are not required. At begin­
ning of each exercise session, the finger is passively flexed
10–30 times to lessen the overall resistance of finger joints and
soft tissues during subsequent active flexion. The passive
motion is followed by actively flexing the finger with gentle
force 20–30 times up to the range the patients feel comfortable
with (usually from full extension to one-third or one-half of
entire flexion range, and may even increase to two-thirds if
achieved with ease). Active flexion over full range is not
encouraged, unless it can be achieved very easily. In this 2.5-
week period, full active extension is particularly encouraged,
and prevention of extension deficits rather than achieving full
range active flexion is emphasized.
After 2.5 weeks (or 3 weeks, or slightly later), a new ther­
moplastic splint is made, and the wrist is splinted at 30°
extension (Fig. 9.44). Exercise of finger flexion, both passively
and actively, is emphasized in this period. Active motion up
to the midrange is required, and can proceed up to two-thirds
(or full range). However, digital flexion from the mid-range
to full range, in particular over the final one-third of the
flexion range, usually is achieved passively. In this period, we
ensure passive flexion over a full range to prevent joint con­
tracture and active flexion over an increasingly greater range
gradually approaching full flexion range, but discourage
active forceful flexion of the finger over the final range where
the tendon is subjected to the greatest load and is more vul­
nerable to rupture (see Figs. 9.8 & 9.43). Differential FDS and
FDP motion exercise is encouraged throughout the first 5
weeks. From the sixth week, full active finger flexion is
encouraged (which can be started earlier when the flexion is
judged to have less resistance). From 6 or 8 weeks, the splint
is removed or used only at night or when going out.
Delayed motion exercises
Delaying motion exercises, i.e., immobilization over the first 2
weeks, can be a right choice for some patients. A patient with
distal zone 1 direct end-to-end repair, the terminal part of
the FDP tendon has little need of gliding and adhesions have
almost no impact on digital motion. The author immobilizes
the wrist in 20–30° of flexion and the MCP joint in slight
flexion for 2 weeks with a short dorsal splint. From the third
week, the digit is passively moved within the splint. From
the fifth week, the patient performs active digital flexion with
the splint removed; the splint is not discarded until week 7.
A severely traumatized hand after repair of multiple struc­
tures also merits from such delayed exercises. The above-
described protocols represent several distinct categories of
exercise. While the key points of the passive–active motion
regime are respected currently (Box 9.7), upon applying to
individual patients, surgeons or therapists should incorporate
refinements. In patients with severe edema of the hand or
trauma to multiple digits, motion exercise can be delayed for
a few days, and more sessions of passive digital motion
should be integrated. Table 9.2 is the straightforward scale
that I use to record the severity of digital edema for setting
timing and intensity of exercise. Other factors such as joint
stiffness, soft-tissue conditions, and extensor tethering should
also be considered in adjusting the regime.212
Strong surgical repairs together with necessary venting of
the pulleys have bestowed greater freedom in wrist positions
after surgery. Often the wrist is put in a neutral position
and a shorter splint is used (to about 10 cm above the wrist)
BOX 9.7  When to begin and how to perform early active motion
• Early active motion of the surgically repaired digit is a
component of an early passive–active motion regime, which
should be performed together with passive motion in each
exercise session with the protection of a dorsal splint (or
out-of-splint exercise in very compliant patients).
• Early active motion should be initiated on day 3, 4, or 5 after
surgery, not necessarily starting on day 1. Delaying the early
motion for a few days decreases pain and avoids peak digital
edema.
• Early active motion can be delayed to around the end of week 1
if remarkable digital edema is drastic and wound conditions do
not allow earlier motion. However, passive hand motion should
be implemented earlier to decrease the risk of joint stiffness and
edema.
• At least 4–6 sessions of exercise are necessary, distributed
across the day and evening. More exercise sessions should be
added if possible.
• In each session, passive motion always precedes active digital
flexion. The finger should be flexed passively and extended
20–30 times (or more) before starting active finger flexion.
• In performing active finger flexion, the patient should be
instructed to perform partial range active flexion in the first 2.5
or 3 weeks, i.e., active flexion over the first one-half or two-third
parts of the entire flexion arc, avoiding the final part of active
flexion or making a fist.
• Full range of active flexion is allowed 3–4 weeks after surgery.

215
Postoperative care
the globe actually use some kinds of variants of these
protocols.149,213 Motion regimes for zone 4 and 5 repairs are
generally not as complex as those described above. There is
not yet universal agreement regarding the timing of initiating
rehabilitation and frequency of motion. Theoretically, tendon
adhesions develop from 10 days to 2 weeks after surgery. No
studies have yet proven the necessity of starting exercise on
the first day. It seems equally reasonable to commence exer­
cise slightly later, though still within one week after surgery.
Likewise, no studies have identified the optimal frequency of
motion in each exercise episode.
Experimental evidence supporting later commencement of
tendon motion were offered by Zhao et al.118 of the Amadio
group, and the author’s colleagues Xie et al.119 and Cao et al.122
Digital edema increases resistance to motion, which peaks at
3 to 5 days.120–122 Both Zhao et al.118 and Cao et al.122 suggest
that motion be commenced later (5 days after surgery).
to protect zone 1 and 2 repairs (Fig. 9.45). Because tendon
repairs are strong, out-of-splint active motion is performed
regularly.
From communications with many hand surgeons and
therapists, the author has found that hand centers around
Fig. 9.44  The author’s combined passive–active tendon motion protocol. This protocol is divided into two 2.5-week periods, or into two 3-week periods when trauma to
the digit is severe or edema of the hand is remarkable. In the first 2.5 weeks, with wrist in slight flexion, finger extension is emphasized. Only partial active digital flexion is
allowed, but full range of passive motion is implemented. In the second 2.5 weeks, with wrist in extension, full active finger flexion is encouraged. This protocol
incorporates the concept of synergistic wrist and finger motion. When the wrist is flexed, finger extension is less tensed; when the wrist is extended, finger flexion is less
tensed.
Emphasis on full active digital flexion
Emphasis on full digital extension
Partial active digital flexion and full passive digital flexion
The Second 2.5 Weeks
The First 2.5 Weeks
Table 9.2  Severity of digital edema
Grades
Descriptions
0 (none)
Swelling is absent
1 (slight)
Swelling is minimal or mild
2 (moderate)
Swelling is prominent, with increase in digital
diameter
3 (severe)
Swelling with openings in skin incisions

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SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
Nevertheless, the past 25 years have seen impressive
improvements in outcomes of flexor tendon repairs. In the late
1980s and early 1990s, Small et al.210 and Cullen et al.213 used
a two-strand repair and postoperative active motion and had
repair ruptures in 6–9% of the repairs, with overall good or
excellent results in 78% of the digits. Elliot et al.211 reported a
series of 233 patients with complete division of the digital
flexor tendons, treated with a two-strand core repair with a
controlled active motion regimen. Thirteen (5.8%) fingers and
five (16.6%) thumbs suffered tendon ruptures during the
mobilization. In the same period, multistrand core repairs
were reported by Savage and Risitano,14 and Tang et al.17,214
together with active or passive–active motion therapies.
Trumble et al.229 used a four-strand Strickland core suture
and a running epitendinous suture to repair zone 2 flexor
tendon lacerations in 119 digits (103 patients) and examined
postoperative therapies in a multicenter prospective random­
ized trial. They documented significantly greater range of
digital motion, smaller digital flexion contractures, and greater
patient satisfaction in the active motion group than in the
passive motion group. Associated nerve injury, multiple digit
injuries, and smoking were factors leading to poorer outcomes.
Patients treated by a certified hand therapist had better motion
Outcomes, prognosis, and
complications
Review of outcomes reported over 25 years showed excel­
lent or good active range of finger motion in more than
three-quarters of primary tendon repairs.14,17,19–21,25,210,211,213–232
Nevertheless, repair ruptures were documented in a majority
of the reports. In the earlier part of this period, the rupture
rates ranged from 4 to 10% in the finger flexors and from
3 to 17% in the FPL tendon of thumbs.14,17,214–228 Adhesions
remained the most common complication, preventing satis­
factory return of active joint motion. Finger joint stiffness
was reported fairly frequently as well. It is worth noting that
most of these reports came from the finest hand centers in the
world, and each team was supervised by at least one surgeon
with expertise in treating tendon injuries. The outcomes in a
general hospital setting may actually reflect a lower level of
success. Flexor tendon repairs might have been unsuccessful
in a larger proportion of patients, with a greater incidence
of repair ruptures, adhesion formations, or digital joint
contracture.
Fig. 9.45  The postoperative protection and motion. (A) Neutral wrist position with a
short forearm splint. (B) Out-of-splint motion exercise is allowed. (C) In later weeks,
specific motion exercise of the distal interphalangeal joint is often necessary to
correct mild to moderate stiffness, which develops 3 to 4 weeks after surgery.
A
B
C

217
Secondary procedures
motion, as well as grip strength and quality of motion, into
the grading system (see Table 9.3).19
Outcomes of flexor tendon repairs are affected by patient
age, extent and zones of injuries, timing of the repairs, post­
operative exercise, and the expertise of the surgeon. Results
of tendon repairs in children are generally better than those
in adults. Tendon repairs associated with extended soft-tissue
damage or accompanied by phalangeal fractures are likely to
have worse outcomes.
Secondary procedures
Secondary tendon repairs are achieved by free tendon
grafting or staged reconstruction. These procedures are
reserved for tendons that could not be repaired primarily
or for lengthy tendon defects (Box 9.10). These techniques,
developed by the early masters of hand surgery,38–42,233–243
remain largely unchanged today despite refinements in
tendon junction methods, use of novel suture materials, and
widespread adoption of postsurgical rehabilitation in recent
decades.244–248
and less severe contractures. Two digits had tendon ruptures
in each group. The study supports the combination of multi­
strand tendon repair and early active motion after zone 2
repairs. Reports over the recent years give further support to
early active digital motion.230–232 Rupture rates do not increase
in tendons with strong surgical repair and early active
flexion.230–232 The wrist can be placed in a neutral position or
may simply use a hand-based splint after tendon repairs in
the digits. Robust tendon repairs and venting the narrow part
of the annular pulleys actually result in greater freedom of
hand position and motion, and minimize the risk of repair
ruptures.
Of note, reports of multistrand core sutures in recent years
documented minimal or zero repair ruptures. A stronger
surgical repair combined with release of the pulleys offered
great safety to the postoperative active motion exercise. After
combined use of multistrand repairs and pulley releases, the
majority of the cases had good to excellent active range of
digital motion with zero tendon ruptures.19,24,25 The author’s
own clinical outcomes also indicate that good-to-excellent
return of function can be achieved fairly consistently by
means of multistrand tendon repairs, venting of pulleys, and
well-designed combined passive and active motion protocols
(Boxes 9.8 & 9.9). Strickland and Glogovac criteria (Table 9.3)
are the most commonly used methods in assessment of out­
comes.15 The Moiemen and Elliot criteria (Table 9.3),20 which
specifically evaluate the active range of flexion of the DIP
joint, are favored by surgeons who record outcomes of zone
1 repair. The TAM (total active range of motion) method
proposed by the American Society for Surgery of the Hand is
also used, and the Buck-Gramcko method is used often by
German-speaking hand societies.153 Among the less popular
methods currently used are White, Tubiana, and tip-to-palm
distance methods. The author currently uses a criterion that
implements a more stringent measure of range of active finger
BOX 9.8  Methods to optimize outcomes
1. Master tendon anatomy in detail and use atraumatic techniques
throughout surgery.
2. To expose the tendons, open a window in the synovial sheath,
or open the A2 partially or the entire A4 pulley if the repair site
overlaps or is located just distal to these structures.
3. May release the distal two-third parts of the A2 pulley, where it is
the most narrow and most constrictive to the tendons, when the
FDP tendon is cut just distal or under the pulley.
4. Adopt a stronger and more secure core suture method.
5. Add peripheral sutures to smooth the repair and to prevent gap
formation.
6. Properly combine passive and active finger motion into
postoperative motion protocols. Fully extend and flex the finger
passively, followed by active finger flexion over a certain range.
Active motion over the final one-half or one-third is discouraged
in the initial weeks to avoid tendon overload (rupture).
Postoperatively, apply motion therapy for at least 5–6 weeks.
7. Passive finger motion before active motion substantially
decreases the overall resistance to digital motion, lessening the
chance of repair ruptures during active motion.
8. Surgical tendon repairs are performed by experienced surgeons,
and the unit should have established postsurgical rehabilitation
guidelines.
BOX 9.9  What are the most important factors during surgery?
1. Two essential goals must be achieved: maintaining sufficient
purchase length (> 0.7–1.0 cm) of the core suture – most vital
for the suture’s anchor in the tendon, and maintaining tension in
the sutures placed in the tendon – critical to prevent gapping
between stumps.
2. The suture’s holding – a grasp or a lock – in the tendon should
be at least 2 mm or greater. Small grasps or locks are pulled
out easily.
3. Increasing the diameter of suture from 4-0 to 3-0 can increase
the core suture strength; but with sutures of either caliber, at
least four strands are needed for any zone 1–3 repairs.
4. Even a robust repair may fail if the tendon impinges against a
pulley or is tightly constricted by narrow pulleys. Therefore,
properly venting pulleys when necessary is just as important as
employment of a robust repair.
BOX 9.10  Secondary surgery: grafting and staged reconstruction
Indications
1. Tendon injuries not treated within 1 month after injury
2. Rupture of the tendon repairs at primary or delayed primary
stages
3. Tendon injuries not indicated for primary repair
4. Badly scarred digits
Essential requirements
1. Supple passive motion of the hand
2. Good soft-tissue condition
3. Sufficient time after initial tendon injury: at least 3 months
Contraindications
1. Limited joint motion
2. Presence of soft tissue wounds or defects, and fractures not
well-healed

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SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
Donor tendons
The donors are palmaris longus, plantaris, long toe extensors,
or in rare instances the FDS tendon from a normal finger (Figs.
9.46 & 9.47). The palmaris longus tendon (about 15 cm) from
the ipsilateral limb is a frequently used donor and is appropri­
ate for a palm-to-fingertip graft. It can be easily harvested
through a short transverse incision over the tendon just
Table 9.3  Criteria of assessment of functional outcomes of flexor tendon repairs
% Return of motion*
Grip strength†
Quality of motion‡
Function grade
Strickland criteria (1980)
85–100 (>150°)
Excellent
70–84 (125–149°)
Good
50–69 (90–124°)
Fair
0–49 (<90°)
Poor
Moiemen–Elliot criteria (2000) for zone 1 injuries, the distal interphalangeal (DIP) joint only
85–100 (>62°)
Excellent
70–84 (51–61°)
Good
50–69 (37–50°)
Fair
0–49 (<36°)
Poor
Tang criteria (2007)
90–100
+
Excellent or good
Excellent +
−
Poor
Excellent −
70–89
+
Excellent or good
Good +
−
Poor
Good −
50–69
Fair
30–49
Poor
0–29
Failure
Function is graded as excellent or good when either the grip strength is − or quality of motion is “poor”.
*Percentage return of the normal (contralateral) hand. Strickland and Tang criteria use sum of active range of motion of the DIP and proximal interphalangeal joints.
Moiemen–Elliot criteria use motion of the DIP joint only.
†Grip strength is recorded as + when it is greater than that of the contralateral hand (the nondominant hand), or over 70% of that of the contralateral hand (dominant
hand). Otherwise, grip strength is considered abnormal and recorded as −.
‡Quality of motion is rated on the basis of direct observation of finger motion by surgeons. It is recorded as “excellent” when all three aspects – motion arc, coordination,
and speed – are normal; as “good” when any two are normal; and as “poor” when only one, or none, is normal.
Fig. 9.46  Harvesting a tendon graft through a small skin incision, using a tendon
stripper.
Palmaris longus tendon
Skin incision
Tendon stripper
Free tendon grafting
Indications and contraindications
Most traumatic lacerations of the digital flexor tendons are
now treated with end-to-end tenorrhaphy primarily. Only
some cases require secondary repairs by means of free tendon
grafting. Tendon grafting is indicated (1) when the lacerated
tendons are not treated during primary or delayed primary
stage, (2) when the primary repairs have ruptured and cannot
be re-repaired directly, and (3) in the cases with severe
contamination, infection, lengthy loss of tendon substance,
extensive destruction of the pulleys, or accompanying injuries.
Patients who have serious scarring in the tendon bed or failed
previous efforts at secondary flexor tendon procedures are
appropriate for a staged tendon reconstruction, rather than
one-stage tendon grafting. Surgeons sometimes need to decide
according to intraoperative findings.
Before surgery is attempted, the soft tissue wound should
be well-healed, with supple passive motion of the hand.
Physical therapy is prescribed to improve the range of motion
of the digits if passive joint motion is limited substantially.
Boyes42 classified the conditions associated with the cases of
tendon grafts and surgical prognosis is worsened by poor
hand condition. Lack of passive range of joint motion is
contraindicated for one-stage tendon grafting, but may be
suitable for staged tendon reconstruction. The timing of
tendon grafting is usually 3 months after injury.

219
Secondary procedures
proximal to the flexion crease of the wrist. The tendon is
divided and grasped with a hemostat, while a tendon stripper
is advanced slowly into the proximal forearm. Care must be
taken to protect the median nerve trunk lying beneath the
tendon and its cutaneous branch of the median nerve.249
Because this tendon is absent in about 15% of all hands,250
examination to confirm its presence is essential before surgery.
The plantaris tendon is equally satisfactory for a graft, which
is obtained by an incision medial to the Achilles tendon and
use of a tendon stripper. The length of this tendon (25 cm) is
well-suited for a long distal forearm–fingertip graft. However,
this tendon is absent in 7–20% of limbs, and its presence
cannot be predicted preoperatively.251,252 Extensor digitorum
longus tendons to the second, third, and fourth toes, the
extensor indicis proprius, the extensor digiti quinti proprius,
and the FDS tendon to the fifth finger can be used as well. In
my clinic, I use the palmaris longus tendon most frequently
and place the proximal junction in the palm.
Operative techniques
The flexor tendon is exposed through a volar Bruner’s inci­
sion or the midaxial approach.253–257 Integrity of the major
annular pulleys is important to the function of the graft. At
Fig. 9.47  Three common donors of tendon grafts: (A) palmaris longus tendon;
(B) plantaris; and (C) toe extensors.
A
B
C
least the A2 and A4 pulleys should be preserved. If possible,
other annular pulleys such as A1 or A3 and a part of the
synovial sheath are preserved to foster better gliding of the
grafted tendon. If a series of annular pulleys are found to be
destroyed, reconstruction of pulleys is necessary. Most cases
requiring the reconstruction need to be preceded by staged
tendon reconstruction.
The distal junction of the graft is placed at the fingertip.
The common method is to suture the graft directly to the
residual FDP stump or to bury it under an osteoperiosteal flap
in the volar phalanx (see Fig. 9.14).257–259 In the latter case,
straight Keith needles are passed through the distal phalan­
geal drill hole and exit over the proximal portion of the nail.
After emerging from the nail surface, the needles are passed
through a gauze pad or a sponge, and through the holes of an
overlaying button. The sutures are tied over the button to
anchor the graft. Additional sutures are used to secure the
FDP tendon stump to the graft. Alternative methods are avail­
able, as shown in zone 1 repair (see Fig. 9.14).157,159,160,243 In
children, because drill-holes in the distal phalanx may damage
the open epiphyses, the graft is sutured directly to the stump
of the profundus instead. Either at the palm or in the forearm,
the proximal junction of the graft is achieved by a Pulvertaft
weave suture to the proximal stump of the flexor tendon (Fig.
9.48). Placement of the junction at the palm requires a shorter
graft and preserves the function of lumbrical muscles. Care is
taken to avoid suturing the tendon to the lumbrical muscle,
because this tends to increase the tension in the muscle. Place­
ment of the junction distal to the wrist allows easy adjustment
of the tension of the graft, and the scar may be less severe. In
the author’s experience, a Pulvertaft weave suture is appro­
priate for the proximal junction in both areas (Fig. 9.49), and
the finger is held in slightly greater flexion than in the resting
position when the proximal stump is sutured (Fig. 9.50).
Postoperatively, the wrist is held in a position of 30–40°
flexion, the MCP joints flexed to 60–70°, and the IP joints at
rest in almost full extension. The traditional recommendation
is 3 weeks of immobilization within a dorsal splint applied
from the fingertip to below the elbow, followed by active
exercise of the digits with the protection of a dorsal blocking
splint. Some surgeons advocate passive or active finger
motion under cautious supervision from a few days after
surgery if the graft junctions are strong. Most surgeons still
prefer to immobilize the grafted digits for at least 3 weeks to
avoid tension on the tendon and to allow some revasculariza­
tion of the graft. More vigorous exercise can be instituted at
6 weeks after surgery.
The need for tendon graft or reconstruction is controversial
when the superficialis tendon is fully functional, but the FDP
tendon is cut and has not been repaired directly within 3 to 4
weeks after trauma.260–266 There is a risk of losing function if
a profundus graft fails. However, such operations are worth
the risk in selected cases, such as in young people with a
reasonable need for active DIP joint flexion. The procedures
are similar to those described above. A thinner donor tendon
is preferable and the A2 pulley can be shortened, but a series
of pulleys are preserved (Fig. 9.51). Alternatively, one slip
of the FDS tendon can be removed to favor passage of the
graft. During the procedure, while passing the graft through
the FDS tendon, injury may occur that results in formation
of adhesions and a loss of finger function. Overall, caution
must be exercised with patient selection. Patients with intact

220
SECTION II
CHAPTER 9 • Flexor tendon injuries and reconstruction
Fig. 9.48  Skin incision and the method of free tendon grafting to reconstruct the
function of digital flexion. As many annular pulleys as possible are preserved.
(A) The tendon junctions are placed outside of the flexor sheath region. To make a
proximal junction of the graft with the end of a digital flexor tendon, the Pulvertaft
weave technique is commonly used (shown in detail in B). The junction is placed
at either palm or distal forearm. The graft was woven with the digital flexor through
holes in the tendons created by a knife (B – top to bottom).
A
B
Distal tendon to
bone junction
Proximal tendon to
tendon junction
superficialis tendon may adapt nicely and require no treat­
ment. Surgeons should fully inform patients about expected
gain of function versus risks of this operation.
When the superficialis tendon is intact and the DIP joint is
not stable, the DIP joint can be fused or tenodesed in slight
flexion. In the presence of a functional FDS tendon, the com­
bination of MCP and PIP joint motion produces approximately
85% of the arc covered by the finger in flexion.
Staged tendon reconstruction
Indications
This operation is indicated in cases with badly scarred digits,
as a result of injury or multiple failed attempts to restore
tendon continuity and gliding. The techniques were devel­
oped in the middle of the 20th century by Bassett and Carroll,
Hunter, Paneva-Holevich, Schneider, et al.44,267–278 This opera­
tion consists of procedures in two stages. In the first stage, the
tendon and scar from the tendon bed are excised, but the
pulleys are preserved or reconstructed. A Dacron-reinforced
silicone tendon implant is inserted into the tendon bed to
maintain the tunnel and to stimulate the formation of a
mesothelium-lined pseudosheath. Following maturation of
the sheath, a tendon is grafted in lieu of the implant in the
second stage.
Techniques
The first stage
The involved finger is exposed through a volar zigzag incision
and the incision is continued to the lumbrical origin level of
the palm (Fig. 9.52). The tendons and sheath (pulleys) are
usually found embedded within scars. The tendons are
excised with a 1-cm stump of the profundus tendon retained
at its distal insertion. The critically located annular pulleys are
carefully dissected out of scars. All potential useful pulley
materials are preserved. When a series of pulleys are damaged,
critically located pulleys (A2 and A4) should be reconstructed,
which is an important part of the reconstruction. One method
is to use a tendon graft, either a portion of an excised flexor
tendon or the palmaris longus tendon, and wrap it around the
phalanx twice to obtain sufficient width, but place it deeper
than the extensor mechanism in the proximal phalanx or
superficial to the extensors in the middle phalanx (Fig. 9.53).
Another method is to make use of one rim of a residual pulley,
and a tendon graft or a part of the extensor retinaculum is
woven back and forth to form a volar part of the residual
pulley. A slip of the FDS tendon can be used to make a pulley
as well. In the presence of flexion contracture of the finger
joint, check-rein extensions of the palmar plate and the acces­
sory collateral ligaments are divided to release the contracture.
The profundus tendon is transected at the midpalm.
A set of tendon implants is then tried to determine the
appropriate size of the implant, which is judged by the tight­
ness of the digital pulleys and the expected size of the tendon
graft in the second stage. In adults, 4-mm implants are often
used, which are close in size to the tendon graft. After inser­
tion of the implant underneath the pulleys, the implant should
be movable in the tendon bed with minimal resistance. The
distal anchor of the implant can be created in several ways
(Fig. 9.54). A second incision is made in the distal forearm.

Fig. 9.49  A case of free tendon grafting with a Pulvertaft weave junction of the graft with a digital flexor tendon in the palm. (A) The graft was woven into the digital flexor
tendon. (B,C) Two sutures were added in either side of the graft and the digital flexor. (D) Completion of the weave tendon repair.
A
B
C
D
Fig. 9.50  Tension status of the fingers at the time of suturing the proximal tendon
junction of a graft. With the wrist in neutral position, the fingers are slightly more
flexed than at the resting position, with each finger falling into slightly more flexion
than its radial neighboring fingers.
Fig. 9.51  A case of reconstruction of the flexor digitorum profundus tendon in the
presence of an intact flexor digitorum superficialis (FDS) tendon. A palmaris longus
tendon was harvested as a graft. A series of pulleys (A4, a part of the A2, and A1)
were preserved. The thin palmaris longus tendon fits well within the pulleys and
intact bifurcating FDS tendon in the finger.