Operative Technique in Plastic Surgery – Kevin C.Chung

motor re-education.
Positioning
■ The patient is positioned supine on operating table with the affected arm
extended and supinated on an armboard.
Approach
■ The entire procedure is completed through a single incision designed
longitudinally or zigzag over the course of the FCU and ulnar neurovascular
bundle in the distal 1/3 of the volar forearm (FIG 3).
FIG 3 • Surgical approach for AIN to ulnar motor nerve
transfer.
T E C H N I Q U E S
■ Distal Exposure Including Identification of the
Motor Component of the Ulnar Nerve
■ A longitudinal incision is made in the distal 1/3 of the volar forearm over the
course of the flexor carpi ulnaris (FCU) and ulnar neurovascular bundle
including a short zigzag segment across the wrist crease.
■ The pisiform and hook of the hamate are marked, and a longitudinal incision
between them is made to approach the Guyon canal. Sharply dissect the
overlying fascia at the level of the wrist crease, exposing the ulnar
neurovascular bundle.

■ The ulnar neurovascular bundle is identified and retracted ulnarly.
■ The deep motor branch is released by dividing the leading edge of the
hypothenar musculature off of the hook of the hamate.
■ The motor branch is then identified and traced proximally. Either manual or
visual neurolysis can be performed to identify the motor component of the
ulnar nerve 9 cm proximal to the wrist crease.
■ The motor component of the ulnar nerve is marked with a vessel loop 9 cm
proximal to the wrist crease (TECH FIG 1).
TECH FIG 1 • Identification of the motor component of
the ulnar nerve (vessel loop).
■ Proximal Exposure Including Identification of the
Anterior Interosseous Nerve
■ Through the same incision, identify the finger flexors and retract them
radially to identify the pronator quadratus (PQ) muscle. Some muscle fibers
of the flexor digitorum profundus (FDP) may have to be released to gain
better visualization of the proximal PQ and anterior interosseous nerve
(AIN).
■ At the proximal edge of the PQ, identify the AIN entering the muscle.
■ Carefully divide the PQ with bipolar cautery for 1 to 2 cm (proximal to
distal) superficial to the AIN to maximize AIN length for transfer (TECH

FIG 2).
■ Divide the AIN distally just prior to its branching point, which is typically at
the halfway point of the PQ.
TECH FIG 2 • Division of the pronator quadratus to
reveal the distal extent of the AIN (upper blue
background).
■ End-to-End Transfer of the AIN to the Motor
Component of the Ulnar Nerve
■ Transfer the AIN ulnarly across the PQ to the ulnar nerve 9 cm proximal to
the wrist crease (TECH FIG 3A).
■ Ensure adequate length to perform transfer with no tension.
■ Divide the motor component of the ulnar nerve as proximally as necessary to
ensure adequate length to perform transfer with no tension.
■ Intrafascicular dissection of the ulnar motor fascicle distally will allow for a
tension-free coaptation.
■ Perform neurorrhaphy with a microscope using 9-0 nylon suture (TECH
FIG 3B).
■ Evaluate the neurorrhaphy site while performing a full pronation-supination
arc to ensure no tension at any forearm position.
■ Close skin in standard fashion, and either a soft dressing or volar wrist splint

is placed.
TECH FIG 3 • A. Division of the AIN. B. End-to-end
neurorrhaphy of AIN to motor component of ulnar
nerve.
■ Reverse End-to-Side AIN to Ulnar Motor Nerve
Transfer4
■ Consider reverse end-to-side transfer in patients in whom ulnar nerve
recovery is ultimately expected. Also, in high ulnar nerve injuries where
distal intrinsic recovery is possible, the distal reverse end-to-side AIN nerve
transfer can be performed to help “babysit” the motor endplates in the hand
until the more proximal regenerating axons can reach the hand.
■ When performing a reverse end-to-side nerve transfer, the skin incision
should be longer, and the ulnar nerve exposure should be more proximal. To
obtain a tension-free reverse end-to-side nerve transfer, the AIN will have to
be transferred more proximally to reach the ulnar nerve than in an end-to-end
transfer.
■ Instead of dividing the ulnar motor component, create epineurial and
perineurial windows in the motor component of the ulnar nerve.
■ Transfer the AIN to this epineurial/perineurial window ensuring no tension.
■ Perform neurorrhaphy of the AIN to the side of the ulnar motor component
with a microscope using 9-0 nylon suture (TECH FIG 4).
■ Evaluate the neurorrhaphy site while performing a full pronation-supination
arc to ensure no tension at any forearm position.

■ Close skin in standard fashion, and either a soft dressing or volar wrist splint
is placed.
TECH FIG 4 • A,B. End-to-side neurorrhaphy of AIN to
motor component of ulnar nerve.
PEARLS AND PITFALLS
Nerve
transection
■ Remember that the Donor nerve (AIN) is always cut Distal and
the recipient nerve (ulnar motor branch) is always cut proximal.
Guyon canal
release
■ It is important to perform a full Guyon canal release to prevent a
distal conduction block on the recovering nerve.
Reverse end-
to-side
transfer
■ Consider a reverse end-to-side transfer in patients in whom ulnar
nerve recovery is ultimately expected.
Tension
■ Ensure no tension on neurorrhaphy site while observing a full
pronation-supination arc.
Postoperative
rehabilitation
■ Ensure that you have a hand therapist knowledgeable in motor re-
education for optimal outcomes.
POSTOPERATIVE CARE
■ If a splint was used, the postoperative splint can be removed and gentle range
of motion can be initiated 1 week after surgery.

■ Once postoperative pain has subsided at 3 to 4 weeks, the patient begins motor
re-education under the care of a knowledgeable hand therapist.
OUTCOMES
■ There are limited outcomes data for this procedure, but most case series report
return of intrinsic function within 1 year of surgery.
COMPLICATIONS
■ The most common complications are infection, bleeding, and lack of
reinnervation of the intrinsic musculature.
REFERENCES
1. Haase SC, Chung KC. Anterior interosseous nerve transfer to the motor
branch of the ulnar nerve for high ulnar nerve injuries. Ann Plast Surg.
2002;49(3):285-290.
2. Brown JM, Yee A, Mackinnon SE. Distal median to ulnar nerve transfers to
restore ulnar motor and sensory function within the hand: technical nuances.
Neurosurgery. 2009;65(5):966-977.
3. Novak CB, Mackinnon SE. Distal anterior interosseous nerve transfer to the
deep motor branch of the ulnar nerve for reconstruction of high ulnar nerve
injuries. J Reconstr Microsurg. 2002;18(6):459-464.
4. Davidge KM, Yee A, Moore AM, Mackinnon SE. The supercharge end-to-
side anterior interosseous-to-ulnar motor nerve transfer for restoring intrinsic
function: clinical experience. Plast Reconstr Surg. 2015;136(3):344e-352e.

36
CHAPTER
Nerve Transfers for High
Radial Nerve Palsy
Shelley S. Noland and Jason H. Ko
DEFINITION
■ High radial nerve palsy limits hand and wrist function with loss of wrist,
finger, and thumb extension.
■ The presence of a wrist drop significantly decreases finger flexion power and
grip strength.
■ The inability to open the hand to initiate grasp makes tasks of manual dexterity
difficult.
■ Distal transfer of median-innervated nerve branches to branches of the radial
nerve can preserve motor endplates and restore motor function.
ANATOMY
■ Radial nerve
■ Originates from the posterior cord of the brachial plexus
■ Courses between the humerus and the triceps and innervates the triceps
muscle
■ Travels in the spiral groove posterior to the humerus and exits through the
lateral intermuscular septum about 10 cm proximal to the lateral epicondyle
■ Passes between the brachialis and brachioradialis (BR) and gives off the
following branches:
• BR muscle branch
• Extensor carpi radialis longus (ECRL) muscle branch (at the level of the
interepicondylar line)
■ Enters the forearm by passing anterior to the lateral epicondyle and gives off
the following branches (FIG 1):
• Radial sensory nerve (RSN) branch, which courses underneath the BR

• Extensor carpi radialis brevis (ECRB) muscle branch (about 3 cm distal to
the interepicondylar line)
• Supinator muscle branches (1–2; just proximal to the leading edge of the
supinator)
■ Continues as the posterior interosseous nerve (PIN) and innervates all hand
and wrist extensors
■ Median nerve
■ Originates from the medial and lateral cords of the brachial plexus
■ Courses anterior and medial to the brachial artery
■ Travels between the brachialis muscle and the medial intermuscular septum
■ Gives off the pronator teres (PT) muscle branch at the level of the
interepicondylar line
■ Courses under the lacertus fibrosus, through the superficial and deep heads of
the (PT), and underneath the tendinous arch of the flexor digitorum
superficialis (FDS) and gives off the following branches (see FIG 1):
FIG 1 • Anatomy of the median and radial nerves in the

forearm.
• FDS muscle branches (2–3) from the ulnar side of the median nerve
• Flexor carpi radialis (FCR) muscle branch
• Palmaris longus (PL) muscle branch (if PL is present)
• Anterior interosseous nerve (AIN) from the dorsal radial side of the nerve
• Branches 3 cm distal to the intercondylar line
• Contains fascicles to the flexor pollicis longus (FPL), flexor digitorum
profundus (FDP; index and middle finger only), and pronator quadratus
(PQ)
• Palmar cutaneous branch in distal forearm
■ Enters the hand at the carpal tunnel and divides into the recurrent motor
branch and sensory branches
PATIENT HISTORY AND PHYSICAL FINDINGS
■ History
■ Obtain history of trauma, tumor, or other injury to the affected extremity.
■ Ask location, timing, frequency, and duration of sensory symptoms including
numbness and tingling.
■ Rule out other causes of symptoms such as cervical spine, shoulder, or
brachial plexus issues.
■ Elicit a history of the etiology of the radial nerve palsy.
■ Determine the timeline of injury.
■ Physical examination
■ Perform full motor exam of bilateral upper extremities.
■ Assess for a Tinel sign along the course of the radial nerve.
■ Perform a full motor and sensory examination of the entire affected
extremity.
• Determine the level of the injury.
• If the patient has a wrist drop, it is likely a high radial nerve palsy
occurring prior to the innervation of the ECRL and ECRB (FIG 2).
• If the patient can extend the wrist, he or she likely has a PIN palsy with
preservation of ECRL and ECRB function.
• Perform full sensory exam of bilateral upper extremities documenting 2-
point discrimination and/or Semmes-Weinstein monofilament testing in all

nerve distributions.
• Sensory disturbances in radial nerve lesions typically involve the dorsal
radial aspect of the thumb and hand.
• Ensure that the injury is isolated to the radial nerve.
• Test and record function in your potential median-innervated donor nerves
including branches to the FCR, FDS, and PL.
• Test and record function in the median-innervated muscles that may need
to be used for tendon transfers in the event there are no nerve transfer
options including the PT, FCR, and PL.
IMAGING
■ Obtain electrodiagnostic studies to assist with localization of the injury and to
assess severity of the radial nerve palsy.
FIG 2 • Example of wrist drop.
■ EMG can identify the presence and quality of fibrillations, positive sharp
waves, and motor unit potentials. This can be followed over time to determine
reinnervation status.
■ In setting of trauma, traditional x-rays are recommended to evaluate for
fracture, dislocation, or foreign body.
■ In setting of tumor, formal imaging studies such as CT or MRI are warranted
as appropriate.
SURGICAL MANAGEMENT1-3

■ Patients should be monitored from the time of injury for reinnervation of wrist,
finger, and thumb extensors.
■ Patients with no evidence of clinical or electrical reinnervation at 6 to 9
months should be considered for nerve transfers. Alternatively, tendon transfers
can be performed in a delayed fashion and will be discussed in Chapter 39
(FIG 3).
■ The most common nerve transfers for high radial nerve palsy are
■ FCR to PIN
■ FDS to ECRB
■ Lateral antebrachial cutaneous nerve (LABC) to RSN
■ Typically, there are redundant motor branches to the FCR and FDS, so using a
single-donor nerve branch will still leave some function of the FCR and FDS,
which can still be used to power a tendon transfer if the nerve transfer is not
sufficient.
Preoperative Planning
■ Patient counseling regarding the timeline of recovery after nerve transfers is
critical (1 mm/d).
■ Need to coordinate care with a hand or physical therapist for postoperative
motor re-education
Positioning
■ Patient is positioned supine with the arm extended on a hand table.
■ Tourniquet can be used if donor exposure and identification can be
accomplished within 30 to 40 minutes.
■ After 30 to 40 minutes, tourniquet neurapraxia may preclude the use of nerve
stimulation.

FIG 3 • Algorithm for the management of high radial
nerve palsy. Reprinted from Pet MA, Lipira AB, Ko JH.
Nerve transfers for the restorationof wrist, finger, and
thumb extension after high radial nerve injury. Hand
Clin. 2016;32(2):191-207 with permission.
T E C H N I Q U E S
■ Identification, Decompression, and Dissection of
the Median Nerve
■ A straight incision from the lateral antecubital fossa along the medial aspect
of the BR to the midpoint of the forearm is utilized, which provides exposure
of median and radial nerves (TECH FIG 1A).
■ Identify and protect the LABC nerve that runs with the cephalic vein.
■ Identify and retract the BR to identify the RSN and radial vessels beneath
(TECH FIG 1B). This provides visualization of the PT tendon.
■ If PT to ECRB tendon transfer will be performed, the skin incision is

extended distally to visualize the insertion of the PT on the radius.
■ The insertion of the PT is elevated with a strip of periosteum as distally as
possible, and subperiosteal dissection is performed distal to proximal at this
stage for later tendon transfer.
■ Because it takes 6 to 9 months to begin to see motor recovery after these
nerve transfers, the PT to ECRB tendon transfer acts as an immediate
treatment for wrist drop, which can be quite debilitating for patients.
■ This tendon transfer works well and acts as an internal splint until motor
recovery occurs.
■ If the PT to ECRB tendon transfer is not performed, step-lengthening of the
PT tendon should be performed at this point.
■ This allows the superficial head of the PT to be reflected medially,
exposing the deep head of the PT.
■ Release the deep head of the PT to expose and decompress the median nerve
in the proximal forearm.
■ Identify and release the tendinous edge of the FDS to further decompress the
median nerve and allow direct visualization of the nerve branches.
■ Identify the median nerve and dissect it distally to identify the following
branches (TECH FIG 1C):
■ PT, PL, FCR, FDS, AIN
■ Use of a nerve stimulator will help confirm branch identity.
■ It is helpful to loop each branch with a vessel loop in preparation for later
transfer.

TECH FIG 1 • A. Approach for median to radial nerve
transfers. B. Identification of radial sensory nerve. C.
Identification of median nerve branches, including
flexor carpi radialis (FCR) and flexor digitorum
superficialis (FDS), along with radial nerve branches,
including extensor carpi radialis brevis (ECRB) and
posterior interosseous nerve (PIN).
■ Identification, Decompression, and Dissection of
the Radial Nerve
■ Retract the BR laterally and follow the RSN proximally until the main radial
nerve is identified.
■ Divide the transverse radial recurrent vessels that overlie the radial nerve
(“leash of Henry”).
■ Dissect the radial nerve distally and identify the following branches (TECH
FIG 2).
■ ECRB branch: This branch is small and directly radial to the RSN.

■ PIN branch: This branch is larger and radial to the ECRB branch. This
branch dives deep to the supinator muscle.
■ Use of a nerve stimulator will help confirm branch identity.
■ It is helpful to loop each branch with a vessel loop in preparation for later
recipient of nerve transfer.
■ Release the tendinous leading edge of ECRB and supinator muscles (arcade
of Frohse).
■ This is important for maximal mobilization of recipient nerves.
TECH FIG 2 • Coaptation of flexor carpi radialis (FCR)
to posterior interosseous nerve (PIN) and flexor
digitorum superficialis (FDS) to extensor carpi radialis
brevis (ECRB) nerve transfers.
■ Mobilization and Transection of the Donor and
Recipient Nerves
■ Mobilize FCR, FDS, and LABC branches as distally as possible and transect
them distally.
■ This will facilitate a tension-free neurorrhaphy.
■ Mobilize PIN, ECRB, and RSN branches as proximally as possible and
transect them proximally.
■ This will facilitate a tension-free neurorrhaphy.

■ Transfer FCR to PIN
■ Oppose the FCR (donor) and the PIN (recipient) to facilitate a tension-free
repair (see TECH FIG 2).
■ Perform end-to-end coaptation using a microscope and 9-0 nylon.
■ May use two or three sutures followed by fibrin glue
■ This will minimize trauma and foreign body reaction.
■ Perform complete wrist and elbow range of motion to confirm that no
tension is present in any arm or wrist position.
■ Transfer of FDS to ECRB
■ Oppose the FDS (donor) and the ECRB (recipient) to facilitate a tension-free
repair (see TECH FIG 2).
■ Perform end-to-end coaptation using a microscope and 9-0 nylon.
■ May use two or three sutures followed by fibrin glue.
■ This will minimize trauma and foreign body reaction.
■ Perform complete wrist and elbow range of motion to confirm that no
tension is present in any position.
■ Transfer of LABC to RSN (Optional)
■ Oppose the LABC (donor) and the RSN (recipient) to facilitate a tension-
free repair (TECH FIG 3).
■ Perform coaptation using a microscope and 9-0 nylon.
■ May use two or three sutures followed by fibrin glue
■ This will minimize trauma and foreign body reaction.
■ Perform complete wrist and elbow range of motion to confirm that no
tension is present in any position.

TECH FIG 3 • Example of lateral antebrachial
cutaneous nerve (LABC) to radial sensory nerve
(RSN) transfer.
■ Tendon Transfer of PT to ECRB (Optional)
■ The ECRB tendon is identified in the surgical field.
■ The previously elevated distal PT insertion with periosteal strip is identified
and dissected proximally.
■ An end-to-side tendon transfer of the PT to ECRB is performed using three
or four Pulvertaft weaves and secured with 3-0 braided, nonabsorbable suture
(TECH FIG 4).

TECH FIG 4 • Example of pronator teres (PT) to
extensor carpi radialis brevis (ECRB) tendon transfer
(arrow).
PEARLS AND PITFALLS
Preservation of critical
branches
■ It is critical to preserve the pronator teres and anterior
interosseous nerve branches during this operation.
Pronator teres step-
lengthening
■ This is critical to help with identifying the median
nerve and its branches in the proximal forearm.
Decompression of
involved nerve
branches
■ Decompression of involved nerves and branches
facilitates axonal regeneration.
Nerve transection
■ Remember that the donor nerve is always cut distal and
the recipient nerve is always cut proximal.
POSTOPERATIVE CARE
■ Immediately postoperatively, if no tendon transfer has been performed, a soft
dressing is applied, allowing for free motion of the elbow, wrist, and fingers.

■ If the PT to ECRB tendon transfer has been performed, a short-arm plaster
splint should be applied to stabilize the wrist in an extended position.
■ At 2 weeks postoperatively, this should be transitioned to a short-arm cast for
an additional 2 weeks.
■ If no tendon transfer has been performed, 2 weeks postoperatively, initiate
early motor re-education, edema control, scar management, and gentle ROM.
■ It is important to begin motor re-education before reinnervation.
OUTCOMES
■ There are limited outcomes data for this procedure, but most case series report
return of intrinsic function within 1 year of surgery.
COMPLICATIONS
■ The most common complications are infection, bleeding, and lack of
reinnervation of the radial-innervated musculature.
REFERENCES
1. Pet MA, Lipira AB, Ko JH. Nerve transfers for the restoration of wrist, finger,
and thumb extension after high radial nerve injury. Hand Clin. 2016;32(2):191-
207.
2. Davidge KM, Yee A, Kahn LC, Mackinnon SE. Median to radial nerve
transfers for restoration of wrist, finger, and thumb extension. J Hand Surg Am.
2013;38(9):1812-1827.
3. Moore AM, Franco M, Tung TH. Motor and sensory nerve transfers in the
forearm and hand. Plast Reconstr Surg. 2014;134(4):
721-730.

37
CHAPTER
Section IX: Tendon
Conditions
Acute Repair of Flexor
Tendon Injuries
Jacques A. Machol IV, Neal Chen, and Kyle R. Eberlin
DEFINITION
■ Flexor tendon repair has evolved substantially over time. Flexor tendon repair
balances strong tendon healing against adhesion formation. There is a complex
interplay between tendon repair technique and rehabilitation that dramatically
affects the outcome of flexor tendon repair.
■ Biomechanical strength of suture technique
■ The strength of most initial tendon repairs ranges between 30 and 150 N.1
■ The repair may experience forces up to 50 N during rehabilitation.2
■ The strength of flexor tendon repair is related to the number of core strands
crossing the repair site.
■ Strength of repair is related to suture caliber.
■ Locking sutures provide greater biomechanical strength than do grasping
sutures.
■ Epitendinous sutures provide substantial strength to the tendon repair.
■ Venting of the A2 or A4 pulley can decrease friction in the flexor tendon
system and improve clinical results.
■ Similarly, some surgeons elect to excise a slip of the flexor digitorum
superficialis (FDS) tendon to reduce bulk and gliding resistance.
■ Rehabilitation
■ During the first 1 to 3 weeks, up to 50% of initial repair strength is lost if a
tendon is immobilized.

■ Early motion yields superior tensile strengths compared to delayed motion or
immobilization.
■ Pyramidal rehabilitation protocols incorporating advancing force and
excursion are also being used that are even more physiologically demanding
than prior early active motion protocols.
• Pyramidal protocols begin with the lowest stress force exercises and then
progressively advance forces as needed in order to overcome adhesion
formation.
ANATOMY
■ The FDS muscle belly lies in the superficial anterior compartment of the
forearm. It originates from the medial epicondyle of the humerus in the
common flexor tendon and also has attachments on the oblique line of the
radial head and the proximal ulna. This muscle belly is innervated by the
median nerve.
■ The FDS tendon to the small finger is congenitally absent in up to 7% of the
population.3
■ The FDS decussates at Camper chiasm. Here, it envelops the flexor digitorum
profundus (FDP) and inserts with a 180-degree rotation.
■ The FDP originates from the anteromedial surfaces of the ulna, the
interosseous membrane, and the deep forearm fascia. It is located dorsal to the
FDS.
■ The anterior interosseous nerve of the median nerve in most cases innervates
the index and long fingers.
■ The ring and small finger FDPs are innervated by the ulnar nerve.
■ The long, ring, and small FDP tendons share a common muscle belly.
■ The FDP of the index finger is usually separate.
■ The common muscle bellies of the long, ring, and small fingers are important
clinically because of the quadriga phenomenon. If one of these tendons is
shortened, the change in excursion may limit the ability of the other tendons to
flex fully.
■ The flexor tendons have limited blood supply. They are nourished by
segmental, penetrating arteries via the vincular vasculature (FIG 1A).
■ The digital nerve is volar to the digital artery in the finger.
■ A complex pulley system in the distal palm and digits brings the tendons close
to the bone, thus increasing the overall mechanical advantage (FIG 1B).

■ The A5 and C3 pulley systems may require division in zone 1 injuries.
■ Flexor tendon injuries are divided into five zones labeled from distal to
proximal:
■ Zone 1: Insertion of the FDP to the insertion of the FDS. These are
commonly referred to as “jersey fingers.” The Leddy-Packer classification is
used for zone 1 FDP avulsion injuries:
• Type 1: The tendon retracts into the palm; surgery is recommended within 7
to 10 days.
• Type 2: The FDP is at the proximal interphalangeal (PIP) and held by the
vinculum; surgery is recommended within 2 to 3 weeks.
• Type 3: The FDP is located at the A4 pulley and held by the distal phalanx
bone fragment; surgery within several weeks may be acceptable, but earlier
repair is advocated.
• It is possible to have a distal phalanx fracture with tendon avulsion off of
the bone fragment. These are commonly referred to as Leddy-Packer 4
injuries.
FIG 1 • A. Insertion of flexor digitorum profundus (FDP)
and flexor digitorum superficialis (FDS) with vinculum
longus (VL) and vinculum brevis (VB). B. Flexor tendon

pulley systems. A indicates annular, and C indicates
cruciate.
■ Zone 2: FDS insertion to the distal palmar crease (A1 Pulley)
• Much of the study of tendon repair has focused on zone 2 injuries, also
termed “no man’s land.”
• This area is particularly difficult to repair because of the complexity of the
tendons, pulleys, and blood supply in this region.
■ Zone 3: Distal palmar crease to the carpal tunnel
■ Zone 4: Carpal tunnel
■ Zone 5: Wrist to the forearm
PATHOGENESIS
■ Zone 1 flexor tendon injuries often are caused by resistive flexion. The ring
finger is slightly more prominent than other digits during midflexion. It is
theorized this is why jersey fingers affect the ring finger more often than they
do other digits.
■ Flexor tendon injuries are typically caused by sharp lacerations but may also
occur after crush injuries.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The digital cascade should be inspected. The index through small digits should
gently point to the scaphoid tubercle.
■ A passive tenodesis maneuver can be performed. All digits should flex with
wrist extension. If a flexor tendon is injured, it will not reciprocally flex with
wrist extension.
■ FDP is tested by restricting the metacarpophalangeal (MCP) and PIP joints in
extension and asking the patient to flex the digit at the distal interphalangeal
(DIP) joint.
■ FDS is examined by restricting the adjacent digit(s) in extension and asking
the patient to flex the digit. This maneuver utilizes the quadriga effect to limit
excursion of the FDP, thereby relying on the FDS to flex the digit at the PIP
joint.
■ It is important to recognize that incomplete injuries may be missed on clinical
exam.
■ Sensation of the ulnar and radial digital nerves of each digit should be

evaluated. Static two-point discrimination is beneficial in evaluating nerve
transection.
■ Vascularity of the digit can be evaluated by capillary refill. A digital Allen test
can also be beneficial if a single digital vessel injury is suspected.
IMAGING
■ Plain radiographs should be obtained to evaluate for underlying fracture or
foreign body.
■ These may also be used to locate the distal end of FDP if there is a bony
avulsion associated with a jersey finger.
■ Ultrasound or MRI can be used if there is question regarding tendon integrity
that is not apparent on clinical exam.
■ These studies are not routinely obtained in acute, penetrating trauma.
DIFFERENTIAL DIAGNOSIS
■ Usually, the diagnosis is unambiguous based on history and clinical
examination, but injuries may be heterogeneous.
■ Tendon injuries are often accompanied by digital nerve or arterial injuries.
SURGICAL MANAGEMENT
■ There are a large number of tendon repair techniques. We will describe those
techniques we most commonly use: Tajima, modified Kessler, locking cruciate
(Adelaide), and modified Becker (MGH suture).
■ The Tajima or modified Kessler is biomechanically weaker than the other
two suture configurations; however, this suture construct is reasonable in zone
3 to 5 repairs where early motion is not as crucial. We use this suture in cases
that may be time dependent, such as multiple digit replantations, to expedite
the time expended for tendon repair.
■ The locking cruciate offers benefits of a single knot that is buried within the
tendon.
■ The modified Becker is mechanically stronger than the locking cruciate but
requires a larger exposure. One disadvantage is that knots are external to the
tendon and may increase the bulk of the repair.
■ We perform an epitendinous suture in our zone 2 repairs. With a modified
Becker suture, some surgeons place half of the epitendinous suture first before
inserting the core sutures.

Preoperative Planning
■ Obtain a preoperative digital neurologic and vascular exam to evaluate for
injury as these structures are often repaired during the same operative period.
■ Wide-awake surgery (WALANT) is helpful to evaluate tendon repair and
gliding intraoperatively.
■ A pediatric feeding tube is helpful for tendon retrieval and passage through the
intact proximal sheath when the tendon is retracted.
■ One trick is to place the feeding tube in a freezer to improve the stiffness of
the catheter. There are also various funnels that can be used to help pass the
tendon.
Positioning
■ The patient is positioned supine with the arm abducted to 90 degrees on a
padded hand table.
■ A well-padded tourniquet, if used, should be placed on the biceps to avoid
compressing the flexor tendon muscle bellies. Excess forearm pressure will
affect resting tendon tension.
Approach
■ The use of existing lacerations with extensions via Bruner-type incision or
midaxial incision will provide adequate exposure for repair.
■ If skin viability/coverage is in question, a midaxial incision is preferable to
avoid the acute angle at the tip of the flap that can cause tip flap necrosis and
expose the underlying repair.
■ It is important to get adequate visualization of the laceration. We commonly
expose from the MP joint flexion crease to the DIP flexion crease for a
transverse laceration. We find that a large exposure aids in performing an
adequate tendon repair and generally does not hamper outcomes.
■ Consider extending the incision more proximally, by including a separate
carpal tunnel incision if there is concern for retraction into the palm (ie, Leddy-
Packer type 1).
■ One should preserve most of the pulley system in a way to prevent
bowstringing.
■ Some authors will vent the A2 or 4 pulley systems by partially releasing the
pulleys to facilitate gliding of repaired tendon and have reported no
mechanical problems with this technique.

T E C H N I Q U E S
■ Zone I Repair
Primary Suture
■ There should be at least 1 cm of distal tendon stump to use this technique
(TECH FIG 1A).
■ The proximal FDP tendon may or may not be retracted.
■ If retracted, it should be passed back through the pulley system. This may be
completed using a tendon passer or pediatric feeding tube or via suture to pull
through the pulley system.
■ Sometimes, the pulley system is very tight, and it is helpful to use a funnel-
type device to pull the tendon distally.
■ The funnel helps the tendon end enter the pulley system. We have found
this particularly helpful to minimize fraying of the passed tendon, limiting
trauma to the tendon and optimizing tendon gliding.
■ Wrist and digit flexion will help tendon retrieval.
■ A 25-gauge needle is used to maintain the location of the tendon by
preventing retraction.
■ After pulling the tendon into the repair site, the proximal tendon is skewered
with the needle to the tendon sheath to stabilize the tendon (TECH FIG 1B).
Pull-Through Button
■ The preparation of the proximal tendon is the same as previously described.
■ Repair using a pull-through button is indicated if there is no distal stump or
bone fragment for fixation.
■ The insertion site is prepared with a small curette to roughen a portion of
the volar cortical bone to encourage tendon to bone healing.
■ A 3-0 nonabsorbable suture that can glide such as Prolene is placed at least
1 cm from the distal edge of the proximal tendon in a Bunnell weave
fashion. Prolene is used because this suture will slide and can be pulled out
readily during button removal.

TECH FIG 1 • Zone I repair: primary suture. A. Zone 1
flexor digitorum profundus laceration. B. Primary
repair completed.
TECH FIG 2 • Zone I repair: pull-through button. A.
Modified Kessler suture on tendon end (two Keith
needles are used to pass the suture through the bone
end, not shown). B. Suture passed through the distal
phalanx. C,D. Suture tied over gauze dressing and
button.
■ Two Keith needles are then passed through the nail. There are two methods
of passing the needles:
• Some authors pass the needles through bone. They are passed using a drill

parallel to each other through the distal phalanx insertion site through the
nail plate just distal to the lunula. It is important to pass the K-wires in a
relatively acute angle relative to the phalanx (approximately 30 degrees).
If they are passed too perpendicular to the nail and too distally, the DIP
may assume an excessively flexed position (TECH FIG 2A,B).
• Other surgeons pass needles around the distal phalanx as an alternative to
transosseous sutures. This is performed by pushing Keith needles along
the edges of the bone through the nail. The trajectory of the needles should
be aimed in a similar manner when passing through the bone as described
above.
■ The suture is then passed dorsally and tied over a nonadherent dressing and
a tendon button after confirmation that the tendon is fully seating within the
bone trough (TECH FIG 2C,D).
■ Another option for repair is the use of bone anchors.
■ If there is a large bone fragment on the tendon, this may be amendable to
screw fixation into the distal phalanx.
■ This repair can be augmented with a pull-through suture as well.
■ Zone II to V Repair
Tajima
■ The Tajima modification of the Kessler uses two suture strands. If the
proximal tendon is retracted into the palm, we will use a Tajima suture to
draw the proximal tendon stump distally through the pulley system.
■ The sutures are passed as they would for half of modified Kessler, but a
separate suture is used on each side (TECH FIG 3).
■ This technique is often applied when multiple tendons are injured. Sutures
are passed into all of the injured tendons to allow tagging of proximal
structures during exploration of the wound. Usually, once the bony structures
are stabilized, the tendons are passed and then tied.

TECH FIG 3 • Tajima suture repair.
Modified Kessler
■ The preparation of the zone 2 and 3 repairs may be complicated by the
cruciate and pulley system blocking visualization, suturing, or passage.
Generous windows should be made to allow the repaired site glide
postoperatively.
■ Align the proper orientation of the FDP and/or the FDS to prevent twisting
and hold the proximal tendon in place with a 25-gauge needle.
■ One or two slips of the FDS can be repaired at zone 2.
■ Some authors excise slips to maximize tendon gliding and minimize
resistance. Some surgeons always repair the FDS with the rationale that if
the FDP ruptures, the patient can preserve FDS function. Some excise the
FDS to decrease tendon bulk in within the pulley system.
■ In our practice, we sometimes excise the ulnar slip of the FDS tendon
depending on the tendon quality. We make this decision depending on the
degree of tendon bulk and resistance after venting the pulleys.
■ The FDS is repaired using a horizontal mattress suture or a figure-of-8
suture using a 4-0 Ethibond or Tevdek suture.
■ To start the modified Kessler technique, a suture is passed from the radial cut
end of the tendon and exits out the volar surface 1 cm from the end.
■ A transverse pass is then made from the radial side of the tendon
transversely and out the ulnar side. This pass may be made closer to the cut

edge to lock the suture.
■ Another loop is made passing the suture back into the volar aspect of the
tendon and out the tendon end.
■ The mirror image of the suture is passed on the other end and the knot is tied
within the tendon ends (TECH FIG 4).
■ A four-strand repair may be created with the addition of a second suture in
the same pattern or with a horizontal mattress suture.
Locked Cruciate
■ To begin the locked cruciate tendon suture, a 2-mm longitudinal slit is
created 1 cm from the tendon edge and a suture is passed through this out the
tendon end.
■ The needle is then brought through the opposing tendon end and out 1 cm on
the volar aspect.
■ The suture is reinserted a few millimeters distal and lateral to the prior exit
site and crossed through the tendon without locking.
TECH FIG 4 • Modified Kessler suture repair.

TECH FIG 5 • Locked cruciate suture repair.
■ The suture is then reintroduced into the distal end and passed into other
lateral edge across from the prior slit site.
■ The needle is repassed retrograde a few millimeters distal to the insertion
site and brought out the tendon end.
■ This is passed into the opposing end again, looped back into the tendon a
few millimeters distal, and crossed back into the distal tendon without
locking.
■ The needle exits the slit and the knot is tied within the tendon (TECH FIG
5).
■ Slack should be removed from the suture and gapping approximated with
each throw.
Modified Becker/Massachusetts General Hospital (MGH)
Repair
■ This is our preferred core suture technique when possible.
■ The suture is introduced from the volar, radial of the tendon 1 cm from the
cut end.
■ Two epitendinous crisscross sutures are placed on each tendon end, tightened
snugly, and the knot is tied on the outside of the tendon.
■ A second suture passed in the same fashion is completed on the ulnar side of
the tendon creating a four-core suture repair (TECH FIG 6).
■ This repair can be completed with a single-armed suture, but a double-armed
suture will allow safe passes to prevent accidently catching the suture with
subsequent passes during placement of the crisscross epitendinous sutures.
■ A 5-0 or 6-0 monofilament epitendinous suture is often started dorsally prior
to core suture completion. This may be placed after the core suture repair as
well.
■ The use of an epitendinous suture increases repair strength up to 20% and
may improve tendon gliding.

TECH FIG 6 • Modified Becker/Massachusetts
General Hospital (MGH) suture repair.
■ Epitendinous Repair: Running, Running Locking,
and Silfverskiold Suture
■ Running and running locking sutures are typically done with a monofilament
5-0 or 6-0 suture.
■ The epitendon is grasped with the suture, and a knot is tied approximating
the ends. This end may be left free to tie too after completion of the suture
technique as well.
■ The suture is then passed from superficial to deep on one end and then out
deep to superficial on the other with advancement of each throw.
■ Either the suture is tied to the tail of the first throw or a new knot is
created.
■ The running locking is completed in the same fashion, but locking loops
are used instead.
■ The Silfverskiold suture is analogous to a horizontal cross-stitch suture
(TECH FIG 7).
■ It is performed by placing an anchor stitch and then taking 1- to 2-mm
bites perpendicular to the axis of the tendon approximately 1 cm from the
repair site. Tendon passes are always taken toward the surgeon.
■ The following suture pass is taken on the other side of the repair site, and
the starting point is advanced away from the surgeon.
■ About 10 passes are needed to circumferentially encompass the tendon.
■ The epitendinous suture is then tied to the anchor suture.

TECH FIG 7 • A,B. Epitendinous repair with
Silfverskiold sutures.
PEARLS AND PITFALLS
Technique
■ Use a Tajima suture to retrieve retracted tendons if needed. In the
cases of combined injury, the suture is placed during the exploration/
approach, the bone is fixed, and then the suture is passed and tied.
■ Use a pediatric feeding tube or funnel to help pass sutures through the
proximal pulleys.
■ The primary goal of zone 2 tendon repairs is to repair the tendon with
four-core sutures and an epitendinous suture.
■ Use an epitendinous suture to increase repair strength. Consider
placing the dorsal epitendinous suture before the core repair.
■ Avoid traumatic handling of the tendon to prevent epitendinous injury
that may lead to adhesion formation.
■ The A4 pulley may be vented if the A2 pulley is competent.
Therapy
■ In children, we prefer immobilization in a cast rather than an early
motion protocol.
■ If the tendon repair is strong, begin early motion protocols.
■ If the tendon repair is tenuous, a less aggressive motion protocol is
preferred. Adhesions can be addressed with tenolysis later.
POSTOPERATIVE CARE
■ Passive digital flexion-extension results in loads of around 3 N.4
■ Active digital flexion-extension results in loads of about 30 N.4
■ Tendon excursion during passive digital flexion-extension ranges from 3 to 8

mm in vivo.5
■ Hook and straight fist result in greater loads than does composite fist.6
■ Wrist motion results in greater flexor tendon excursion.
■ A postoperative dorsal blocking splint with wrist and digit flexion is applied.
This splint is removed at the first postoperative visit and a thermoplastic or like
dorsal blocking splint is fashioned to initiate therapy.
■ Earlier protocols consisted of immobilization for at least 3 weeks. This
resulted in loss of digit motion due to tendon scarring; therefore, newer
protocols were established to allow excursion and prevent tendon adhesions
■ Kleinert, Duran, and active place-and-hold are commonly employed early
motion regimens. There are many modifications of these protocols as well.
■ If we have high confidence in the repair, we will begin early motion using the
pyramid protocol described by Groth.7
■ If the repair is tenuous, we will use a modified Duran protocol.
■ Overall, the choice of protocol is surgeon and case dependent.
OUTCOMES
■ Chesney et al. reviewed multiple rehabilitation regimens for zone II flexor
tendon injuries. No significant difference existed between early active and
early passive protocols (Duran- and Kleinert-type protocols), and all protocols
resulted with high rates of acceptable range of motion. Duran protocols had the
lowest rate of ruptures during rehab (2.3%).8
■ Starr et al. performed a systematic review of early active and early passive
protocols for all zones of flexor tendon injury. They found that early passive
range of motion protocols had a statistically significantly decreased risk for
tendon rupture but an increased risk for postoperative decreased range of
motion when compared to early active motion protocols.9
COMPLICATIONS
■ Adhesions are the most common complication.
■ Tendon rupture may occur when loading during rehabilitation exceeds the
strength of the repair and the healing tendon. It is sometimes not possible to
distinguish between tendon rupture and adhesions if the proximal tendon stump
scars to the FDS and the proximal phalanx.
■ Quadriga occurs when the FDP is shortened. Because the FDP has a common
muscle belly, once the finger with the shortened FDP has fully flexed, the other

fingers cannot flex any further.
REFERENCES
1. Jordan MC, Schmitt V, Jansen H, et al. Biomechanical analysis of the
modified Kessler, Lahey, Adelaide, and Becker sutures for flexor tendon repair.
J Hand Surg [Am]. 2015;40(9):1812-1817.
2. Evans RB, Thompson DE. The application of force to the healing tendon. J
Hand Ther. 1993;6(4):266-284.
3. Allan CH. Flexor tendons: anatomy and surgical approaches. Hand Clin.
2005;21:151-157.
4. Schuind F, Garcia-Elias M, Cooney WP III, An KN. Flexor tendon forces: in
vivo measurements. J Hand Surg [Am]. 1992;17(2):
291-298.
5. Horibe S, Woo SL, Spiegelman JJ, et al. Excursion of the flexor digitorum
profundus tendon: a kinematic study of the human and canine digits. J Orthop
Res. 1990;8(2):167-174.
6. Greenwald D, Shumway S, Allen C, Mass D. Dynamic analysis of profundus
tendon function. J Hand Surg [Am]. 1994;19(4):626-635.
7. Groth GN. Pyramid of progressive force exercises to the injured flexor
tendon. J Hand Ther. 2004;17(1):31-42.
8. Chesney A, Chauhan A, Kattan A, et al. Systematic review of flexor tendon
rehabilitation protocols in zone II of the hand. Plast Reconstr Surg.
2011;127:1583-1592.
9. Starr HM, Snoddy M, Hammond KE, Seiler JG III. Flexor tendon repair
rehabilitation protocols: a systematic review. J Hand Surg Am. 2013;38:1712,
7.e1-14.

38
CHAPTER
Repair of Multiple Flexor
Tendon Injury at Wrist Zone
V (Spaghetti Wrist)
Jacques A. Machol IV, Neal Chen, and Kyle R. Eberlin
DEFINITION
■ Volar wrist trauma with tendon, nerve, and arterial injuries is often referred to
as a “spaghetti wrist.”
■ Specific criteria for the definition of a “spaghetti wrist” vary in the literature,
with some authors defining it as injury to at least three of the volar wrist
structures including at least one nerve,1,2 with others defining this injury as
inclusive of both median and ulnar nerve injuries at the level of the wrist.3
■ Other authors have defined this injury as involving a minimum of 10
structures in the wrist.
ANATOMY
■ The volar wrist structures include the radial and ulnar arteries, the median and
ulnar nerves (along with the palmar cutaneous branch and the dorsal ulnar
sensory branch), the flexor pollicis longus (FPL), the four flexor digitorum
superficialis (FDS) tendons, the four flexor digitorum profundus (FDP)
tendons, the palmaris longus (PL), the flexor carpi ulnaris (FCU), and the
flexor carpi radialis (FCR) tendons. Any or all of these structures can be
injured with a volar wrist laceration (FIG 1).
■ The superficial nature of these structures and thin cutaneous coverage render
them highly susceptible to penetrating injuries.
■ At the wrist, the FDS tendons to the long finger (LF) and ring finger (RF) are
volar to the FDS tendons to the index finger (IF) and small finger (SF).
■ The FCU is volar to the ulnar artery and ulnar nerve. The ulnar artery is
typically superficial (volar) to the ulnar nerve; it is therefore possible to injure

the FCU and ulnar artery while sparing the ulnar nerve.
■ The palmar cutaneous nerve is often injured.
■ Flexor tendon injuries in the spaghetti wrist are in zone V (see Flexor Tendon
chapter for details)
PATHOGENESIS
■ These injuries are often self-inflicted but also may result from other traumatic
causes.4
■ They often are the result of sharp lacerations but can also be caused by crush
injuries.
■ The mechanism of injury is most often sharp glass lacerations, followed by
knife wounds and saw injuries.
■ The median nerve and FDS tendons are the most commonly injured structures,
because they are located superficially and centrally in the volar wrist.
■ These injuries are more common in males.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A focused history and physical examination is performed with emphasis on the
etiology and mechanism of injury, sensory and vascular examination, and
examination of each individual tendon in the volar wrist.
■ Self-inflicted spaghetti wrist injuries should ideally be identified prior to
surgery. Psychiatry consultation is helpful for management.
■ A thorough vascular examination should be performed including inspection for
color and capillary refill, a Doppler exam with Allen test, and pulse oximetry
of the digits.
■ A formal nerve examination, including evaluation for light touch and two-
point discrimination, intrinsic motor function, and palmar abduction, should be
performed.
■ The surgeon can glean much information about the status of tendon injuries
simply by observing the digital cascade at rest, as the attitude of the digits can
reflect the presence or absence of intact tendons.
■ In these cases, tenodesis testing is not possible usually because the wrist
cannot be flexed or extended because of the injury.
IMAGING
■ Plain film radiographs are obtained to assess for fracture and foreign body.

SURGICAL MANAGEMENT
■ Early definitive surgical management is recommended, particularly in cases of
vascular or nerve injuries.
■ Thorough debridement and removal of foreign material with copious irrigation
is paramount.
■ Identification and labeling of all injured structures is performed; a checklist is
helpful to organize one’s approach and ensure repair of all injured structures.
■ It is important to label the proximal tendons, as the orientation is clear prior to
dissection and may be lost with mobilization. The distal tendon ends are easily
identified by manual traction intraoperatively.
■ The deep structures including the FDP and FPL are repaired first, unless the
hand is dysvascular in which case an arterial repair shunting is performed first
(usually the radial artery).
■ It is important to repair injured structures in a manner that facilitates
microsurgical repair of the nerves and/or arteries.
FIG 1 • Distal wrist axial slice anatomy. Flexor carpi
radialis (FCR), palmaris longus (PL), flexor digitorum
superficialis (FDS), flexor digitorum profundus (FDP),
index finger (IF), long finger (LF), ring finger (RF), small
finger (SF), and flexor carpi ulnaris (FCU).

■ It is important to identify injured structures, repair deep structures, and then
progress to more superficial structures.
■ If microsurgical repair is anticipated, superficial structures such as the FCR
and FCU are repaired last.
Preoperative Planning
■ The aforementioned thorough preoperative examination formulates a concrete,
definitive operative plan.
■ The surgeon and patient should be prepared for vein and/or nerve grafts,
depending on the time elapsed and mechanism of injury.
Positioning
■ The patient is positioned supine with the arm abducted on a hand table; a
tourniquet is used.
■ The ipsilateral lower extremity is prepped sterilely for vein or nerve graft(s), if
needed.
■ The entire forearm to just above the elbow is prepped. This is particularly
germane with distal lacerations near the wrist crease, where the distal tendon
ends may retract into the carpal tunnel.
■ Skin flaps can be retracted with either elastics/hooks or retraction sutures.
T E C H N I Q U E S
■ Exposure
■ The existing wound is extended proximally and distally to provide access to
injured structures.
■ Do not try to limit incisions in these cases. Wide exposure is preferred
(TECH FIG 1).
■ Proximally, the incision is extended in linear, longitudinal fashion often in
the central aspect of the volar forearm.
■ Distally, an extended carpal tunnel incision may aid in mobilization of
tendons for repair and is frequently performed to release of the transverse
carpal ligament in anticipation of postoperative swelling.

TECH FIG 1 • A. Initial wound presentation with
exposed injuries. B. Extension of the existing wound
proximally and distally to provide access to injured
structures.
■ Exploration and Tagging of the Structures
■ The proximal tendons are exposed and tagged with one-half of the preferred
suture technique and labeled (TECH FIG 2A). A four-core strand suture
technique is commonly used.
■ Arteries and nerve are tagged with a small monofilament suture with long
tails.
■ A checklist is used to ensure repair of all structures (TECH FIG 2B).
TECH FIG 2 • A. Tagging of the proximal structures to
ensure proper anatomical repairs. B. Checklist
ensuring repair of all structures.

■ Repair of Injured Structures
■ Tendons are repaired first from deep to superficial, and often from radial to
ulnar under tourniquet.
■ The choice of tendon repair varies based on surgeon preference and
experience but should entail at least four core strands.
■ We prefer a modified Becker, ie, MGH repair for flexor tendons in zone V.
Epitendinous repair is not needed because gliding is not impeded in zone V
and the surgeon needs to expedite the repairs because of the numerous
structures injured.
■ Microsurgical repair of the nerves and arteries is then performed.
■ The tourniquet can be deflated to visualize arterial inflow and endoneurial
bleeding during neurorrhaphy (TECH FIG 3).
■ Meticulous nerve repair is critical; this should be performed by the most
senior surgeon involved in the operation.
■ Care should be taken to avoid fascicular overlap during tension-free
neurorrhaphy.
■ If there is a single arterial injury, we tend to perform vascular repair even
with a perfused hand.
■ We occlude the other major artery for 5 minutes at the time of reperfusion
(for instance, the radial artery following ulnar artery repair) to allow for
anterograde flow into the hand through the fresh vascular anastomosis.

TECH FIG 3 • Status post microsurgical repair.
PEARLS AND PITFALLS
Technique
■ Careful preoperative examination helps surgical planning.
■ Identification and tagging of proximal tendons will ensure correct
repair of structures; a surgical checklist is helpful.
■ Atraumatic tendon and tissue handling will facilitate gliding of
tendons postoperatively.
■ Meticulous epineurial repair following adequate nerve debridement
will optimize chances of neural recovery; care should be taken to avoid
fascicular overlap.
■ Have the contralateral leg prepped if nerve grafts or vein grafts are
anticipated.
Physical
exam
■ An Allen test and thorough nerve exam should be performed
preoperatively.
■ Inspection of the digits can often reveal the extent of tendon injuries.
Therapy
■ Dedicated occupational/hand therapy is required postoperatively; this
will depend on the strength of repair and the patient’s motivation and
compliance with postoperative instructions.
■ Patients with self-inflicted lacerations may require a longer period of
immobilization, sometimes involving casting.

FIG 2 • Eight months (A,B) and 2 years (C,D)
postoperatively.
POSTOPERATIVE CARE
■ Patients are placed in a dorsal blocking “clam digger” splint with the wrist in
20 degrees of flexion, MP joints at 90 degrees of flexion, and PIP/DIP joints
with mild flexion to off-load the tendon, nerve, and arterial repairs. The splint
should extend to the fingertips.
■ Strict elevation and non–weight bearing is emphasized, particularly for
patients with self-inflicted lacerations.
■ Continuous pulse oximetry is utilized for patients presenting with both radial
and ulnar artery injuries or dysvascular hands; aspirin is utilized for 1 month
postoperatively.
■ The specific regimen of postoperative hand therapy is based on the quality of
the repairs and the compliance of the patient; we prefer early active motion
protocols for sophisticated patients who understand the nature of their injury
and 3 to 4 weeks of immobilization for patients with self-inflicted injuries who

are unwilling or unable to follow strict postoperative instructions.
OUTCOMES
■ Functional outcomes depend on the overall severity of injury and number of
injured structures but are often predicated upon the degree of neural recovery
(FIG 2).
■ With sharp injuries, more than 50% of patients will recover protective
sensation, but intrinsic dysfunction is common with ulnar nerve injuries.
■ Digital range of motion and strength can be satisfactory, particularly with early
active motion protocols in compliant patients.4
■ Patients can be expected to have some degree of dysfunction compared to their
premorbid state.
COMPLICATIONS
■ Tendon adhesions and/or stiffness, greatest when patients are immobilized for
extended periods of time postoperatively
■ Tendon rupture, greatest when patients are not compliant with splinting or
therapy instructions
■ Infection and delayed wound healing, greatest with contaminated wounds
■ Pain resulting from neuroma
■ Clawing and intrinsic minus hand secondary to poor ulnar nerve recovery
■ Arterial insufficiency or cold intolerance
REFERENCES
1. Chin G, Weinzweig N, Mead M, Gonzalez M. “Spaghetti wrist”: management
and results. Plast Reconstr Surg. 1998;102(1):96-102.
2. Puckett CL, Meyer VH. Results of treatment of extensive volar wrist
lacerations: the spaghetti wrist. Plast Reconstr Surg. 1985;75(5):
714-719.
3. Hudson DA, De Jager LT. The spaghetti wrist: simultaneous laceration of the
median and ulnar nerves with flexor tendons at the wrist. J Hand Surg Br Eur.
1993;18(2):171-173.
4. Wilhelmi BJ, Kang RH, Wages DJ, et al. Optimizing independent finger
flexion with zone V flexor repairs using the Massachusetts General Hospital
flexor tenorrhaphy and early protected active motion. J Hand Surg.
2005;30(2):230-236.

39
CHAPTER
Staged Flexor Tendon
Grafting and Pulley
Reconstruction
Richard Tosti, Jacques A. Machol IV, and Neal Chen
DEFINITION
■ Flexor tendon reconstruction refers to the restoration of the flexor mechanism
through the use of tendon grafts.
■ Pulley reconstruction is the recreation of the flexor tendon sheath in order to
prevent bowstringing and optimize strength.
ANATOMY
■ Nine flexor tendons originate in the forearm. Flexor pollicis longus inserts at
the base of the distal phalanx of the thumb. Four flexor digitorum superficialis
(FDS) and four flexor digitorum profundus (FDP) tendons insert on the volar
base of the middle and distal phalanges, respectively.
■ The FDS tendons are superficial to the FDP in the hand, but as they enter the
fibrous sheath, the FDS bifurcates into two slips, which are directed dorsally to
their insertion.
■ The flexor tendon sheath is a fibrous tunnel through which the flexor tendons
glide. Composed of annular and cruciate pulleys, the sheath prevents
bowstringing, reduces the flexor moment arm (imparting strength and efficient
excursion), and provides nutrition (FIG 1). The thumb flexor sheath is
composed of annular and oblique pulleys.
■ The flexor sheath extends from the metacarpal head to the distal phalanx.

FIG 1 • Flexor tendon sheath of a finger consisting of
annular and cruciate pulleys.
PATHOGENESIS
■ Acute flexor tendon rupture occurs as a result of trauma, including laceration,
avulsion, crush, or burn.
■ Attritional ruptures may also occur from synovitis, Mannerfelt syndrome,
prominent implants, bony prominences, infections, and neoplasms.
NATURAL HISTORY
■ Following a rupture, the proximal end of the tendon retracts, leaving an empty
space within the sheath.
■ In as early as 3 to 6 weeks, irreversible contracture of the muscle tendon unit,
degeneration, and scarring within the flexor sheath may occur. The tendon
sheath volume will shrink without an intact tendon, which limits passage of
tendons through the sheath after tendon repair.

PATIENT HISTORY AND PHYSICAL FINDINGS
■ Patients lose the ability to flex the finger at the proximal interphalangeal (PIP)
joint or distal interphalangeal joint (DIP) when the FDS or FDP tendons are
disrupted.
■ Often the cascade of the hand is altered. The affected digit assumes a more
extended posture.
■ A skin injury overlies the approximate level of tendon injury
■ “Tenodesis” effect of the hand is lost. When the wrist is passively extended,
the affected finger does not flex.
■ Active motion is lost. FDS rupture is detected by observing loss of PIP flexion
in the affected digit while holding the adjacent digits in extension. Extending
the adjacent digits isolates the FDS because the FDP tendon of the affected
digit is placed at a mechanical disadvantage due to the common origin. FDP
rupture is detected by stabilizing the PIP in extension and observing a lack of
active flexion at the DIP joint.
■ “Tenodesis” testing can also help detect flexor tendon injuries. When the wrist
is extended, the digits should flex reciprocally if the flexor tendons are intact.
If the flexor tendon is lacerated, there will be lack of reciprocal flexion in the
injured digits.
IMAGING
■ Flexor tendon rupture is usually diagnosed by history and physical exam.
■ Radiographs may be helpful to evaluate for avulsion injuries or bony
prominences causing attritional rupture.
■ Computed tomography may also be useful in evaluating for carpal bone spurs
in suspected attritional ruptures.
■ Ultrasound or magnetic resonance imaging may be useful in determining the
level of proximal tendon retraction.
DIFFERENTIAL DIAGNOSIS
■ Adhesions. It is difficult to distinguish between adhesion and rupture
clinically.
■ Intra-articular injury
■ Nerve injury
■ Neuromuscular disorders
NONOPERATIVE MANAGEMENT

■ Elderly, low-demand patients with comorbidities may not have an outcome
worth the overall risk for multiple reconstructive procedures. Additionally,
these patients may not be able to complete a rigorous postoperative protocol.
■ Physical rehabilitation to maximize passive joint motion is critical prior to
tendon reconstruction procedures.
■ Although not considered “nonoperative,” alternative procedures to
reconstruction include joint fusion or digit amputation, which could be
considered for patients with injuries to multiple structures within the digit.
■ Patients with an intact FDS may have reasonable function even if the FDP has
been lacerated. In these situations, no reconstruction is reasonable. If the DIP is
unstable, fusion is an option, but in many cases, this is not necessary.
SURGICAL MANAGEMENT
■ Direct tendon repair should be performed when possible.
■ Single stage tendon grafting can be performed for acute segmental tendon
defects or delayed injuries without excessive retraction and good passive
motion. An intact flexor tendon sheath is required.
■ Two-stage flexor tendon reconstruction is indicated for failed direct repairs in
zone II, severe injuries with concomitant injury to the adjacent bone or joint,
chronic injuries with excessive scarring, or loss of flexor sheath.
■ Two-stage reconstruction was developed because joint contracture, flexor
sheath volume/pulley insufficiency, and tendon length were problems. Two-
stage reconstruction allows the surgeon to address these factors prior to
addressing the tendon.
■ Prior to the first stage, wound healing, and joint contracture are addressed.
The first stage allows for reconstitution of the flexor sheath and pulley
reconstruction.
■ Once a gliding space is established, the second stage of the reconstruction
can be performed with minimal scarring and inflammation.
■ If the tendon is too short, patients will have problems with quadriga, ie, the
tendon excursion for the injured finger would be shorter than the other digits.
When the injured finger was fully flexed, the other fingers would not flex
completely because of the common FDP muscle belly.
■ If the tendon was too long, some patients developed a lumbrical plus finger.
As the FDP contracts, the lumbricals tighten, resulting in paradoxical extension
of the PIP joint through the lateral bands.
■ Flexor tendon reconstruction, although not a perfect solution, is a method that

has more consistent results than these other techniques.
Preoperative Planning
■ If autograft is planned for the procedure, one should ensure the presence and
integrity of the tendon. Many options are possible, but the most common are
palmaris longus, plantaris, and digital long toe extensors of the second, third, or
fourth toes. Allograft tendon is also an option.
■ Plan for a small-caliber graft (4–5 mm diameter).
■ Plan for only one graft.
■ Do not sacrifice FDS if it is found intact.
■ Perform the repairs outside of the tendon sheath.
■ Repair the proximal juncture to the FDP tendon to power the graft.
Positioning
■ Position the patient supine on a hand table with a nonsterile upper arm
tourniquet.
Approach
■ A volar Bruner-style incision is planned along the length of the finger.
■ A separate zigzag incision in the palm or distal forearm may be needed as
well.
T E C H N I Q U E S
■ Single-Stage Tendon Grafting
■ The tendon sheath is approach through a volar Bruner incision (TECH FIG
1A) and must be examined for competency particularly for the A2 and A4
pulleys.
■ If an inadequate sheath is found, a staged reconstruction should be
performed.
■ If single-stage reconstruction with tendon graft is planned, all the finger
joints must have full supple motion and the skin over the tendon sheath
must be soft so that the finger can move smoothly during therapy.
■ The sheath should be preserved as much as possible.