Operative Technique in Plastic Surgery – Kevin C.Chung

Hand Surg Br. 1998;23(6):802-805.
9. Krusche-Mandl I, Kottstorfer J, Thalhammer G, et al. Seymour fractures:
retrospective analysis and therapeutic considerations. J Hand Surg [Am].
2013;38(2):258-264.
10. King HJ, Shin SJ, Kang ES. Complications of operative treatment for mallet
fractures of the distal phalanx. J Hand Surg Br. 2001;26(1):28-31.
11. Stern PJ, Kastrup JJ. Complications and prognosis of treatment of mallet
finger. J Hand Surg [Am]. 1988;13(3):329-334.

6
CHAPTERProximal Phalanx Fractures
John R. Fowler
DEFINITION
■ Proximal phalanx fractures represent 23% of all hand and forearm fractures.1
■ These fractures can be classified by
■ Location
• Extra-articular
• Intracondylar
• Base/epiphyseal
■ Fracture pattern
• Oblique
• Transverse
• Comminuted
ANATOMY
■ The proximal phalanx is the longest phalanx in each finger and has a mild
palmar concavity.2
■ The head of the proximal phalanx has two convex condyles and a central
shallow depression.2
■ Proximal phalanx shaft fractures typically assume an apex volar angulation.2
■ The intrinsic muscles insert on the proximal phalanx base.
■ The central slip pulls the distal fragment into extension.
■ The extensor mechanism (FIG 1) is in direct contact with the proximal
phalanx. Therefore, fracture hematoma and resulting fibrosis may greatly
inhibit gliding of the extensor mechanism.
■ One must consider this close relationship if considering the use of dorsal

hardware.
PATHOGENESIS
■ Phalanx fractures occur through several common mechanisms of injury:
■ Axial load (jamming type injury)
■ Rotational torque
■ Medial/lateral angular force
■ Crush or direct blow
■ The injury mechanism is important for the type of fracture that is created.
Rotational torque typically produces an oblique fracture, while crush/direct
blow mechanisms produce a transverse fracture that may have comminution.
■ Patient age also plays a role in fracture type and location. Pediatric patients
most commonly sustain epiphyseal fractures at the phalanx base, whereas adult
patients more commonly sustain transverse or oblique fractures of the phalanx
shaft.
NATURAL HISTORY
■ Minimally displaced fractures and stable fracture patterns have a high rate of
union with minimal long-term loss of function.
■ Displaced fractures and unstable fractures may lead to nonunion or malunion,
resulting in loss of motion.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The history should carefully document the mechanism of injury and time since
injury. A higher-energy mechanism of injury may indicate greater surrounding
soft tissue damage and the possibility of greater fracture instability. The time
since injury is important, especially in pediatric patients, as delay in surgical
intervention may preclude closed reduction if significant fracture healing
occurs prior to intervention.
■ A careful examination of the skin is important to rule out open fracture that
would necessitate more urgent surgical treatment.
■ The finger is often swollen and ecchymotic from the fracture.

FIG 1 • Extra-articular proximal phalanx shaft fractures
typically assume an apex volar angulation (red arrow).
The lateral band (IT) insertion (green arrow) at the base
of the proximal phalanx results in flexion of the proximal
fragment (blue arrow) and the central slip (CS) insertion
on the base of the middle phalanx pulls the distal
fragment dorsally (yellow arrow). SB, sagittal band; ET,
extensor tendon. (From Harman TW, Graham TJ, Uhl
RL. Operative treatment of extra-articular phalangeal
fractures. In Hunt TR, ed. Operative Techniques in
Hand, Wrist, and Forearm Surgery. Philadelphia, PA:
Lippincott Williams & Wilkins, 2011:287.)
■ Rotational alignment of the finger should be evaluated by asking the patient to
flex the digits. All four fingers should point in the same direction, toward the
scaphoid tubercle.
■ If patients are unable to adequately flex the digits secondary to pain, the
alignment of the fingernails can be compared to the contralateral hand with
the fingers in full extension. Rotational malalignment is not well tolerated and

is an indication for surgical intervention.
■ Finger extension is carefully evaluated. Apex dorsal angulation of the fracture
can result in relative lengthening of the extensor mechanism, resulting in an
extensor lag at the proximal interphalangeal joint.
IMAGING
■ Standard AP, lateral, and oblique radiographs are obtained.
■ Advanced imaging with CT is rarely indicated. CT may be beneficial to
evaluate articular congruity for condyle fractures and phalangeal base
fractures.
DIFFERENTIAL DIAGNOSIS
■ Proximal phalanx fracture
■ Contusion
■ Collateral ligament sprain/tear
■ Arthritis
■ Trigger finger
■ Infection
NONOPERATIVE MANAGEMENT
■ Nondisplaced and minimally displaced fractures without rotational
malalignment may be treated nonoperatively with a cast or custom thermoplast
splint.
■ The risk of prolonged immobilization and resultant stiffness must be weighed
against the risks of surgical intervention.
SURGICAL MANAGEMENT
■ It cannot be overemphasized that the best surgical option is the least invasive
option that provides fracture stability and the opportunity for early range of
motion.
■ Extensive exposure may result in permanent postoperative stiffness.
■ Percutaneous techniques with near-anatomic alignment may be preferred to
open treatment with anatomic alignment.
■ Indications
■ Closed reduction and pinning
• Acceptable alignment can be obtained by closed means.
• Fracture is stable after pinning.

• Of note, a limited incision to reduce the fracture, followed by percutaneous
pinning, is also a treatment option
■ Open reduction with lag screws
• Long oblique fracture with 2:1 ratio of fracture length:phalanx width
■ Open reduction with mini-fragment plate
• Comminution
• Transverse fracture or short oblique not amenable to lag screws or pinning
Preoperative Planning
■ The surgeon should be prepared for both closed and open techniques.
■ K-wires and mini-fragment screws and plates should be available.
Positioning
■ The patient is placed in the supine position with the affected arm on a
radiolucent hand table.
■ Most surgical approaches are from the dorsum of the finger, and therefore the
palm is placed down on the table.
■ The surgeon sits in the axilla (if right handed) or at the head of the bed (if left
handed) to allow the dominant hand to be used to place K-wires.
Approach
■ For the techniques described in this chapter, the dorsal approach is used.
■ Sharp dissection down to the extensor mechanism is performed to develop
thick flaps that are not damaged by blunt dissection.
T E C H N I Q U E S
■ Open Reduction and Internal Fixation of Intra-
articular Proximal Phalanx Condylar Fractures
■ A midlateral incision is made on the side of the condylar fracture.
■ Sharp dissection is carried out down to the extensor mechanism and thick flaps
are raised.
■ The interval between the central slip and lateral band is incised.

■ The fracture site is identified and dorsal capsule incised to evaluate the
articular surface.
■ The collateral ligament is attached to the condyle and is the deforming force.
■ The fracture is reduced under direct visualization.
■ This is accomplished by placing a 0.035-in. K-wire in the fragment and using
it as a joystick to reduce the fracture. The K-wire can then sometimes be
drilled across the fracture site to temporarily stabilize the fracture. However,
often the K-wire is at the wrong angle, and a second 0.035-in. K-wire is
placed across the fracture site.
■ Caution should be exercised when using tenaculum clamps or towel clips as
the condyle fracture fragment is often very small and can be crushed by these
larger clamps.
■ I have found that gentle use of a hemostat to hold the fracture while the
temporary K-wire is placed across the fracture site is useful and typically
does not crush the condyle.
■ Two or three (depending on the size of the condyle fragment) 1.2-mm mini-
fragment screws are placed across the fracture (TECH FIG 1).
■ I do not recommend the use of standard lag screw technique for these
fractures. I only drill the pilot hole and place a neutralization screw. The
fracture fragment is small, and there is little room for error. Multiple passes
with the drill can cause fragmentation of the fracture and results in fracture
displacement.
■ Anatomic reduction is confirmed on orthogonal radiographs.
■ The wound is well irrigated and interval between the central slip and lateral
bands closed with 4-0 Vicryl suture.
■ The skin is closed using 4-0 nylon suture.

TECH FIG 1 • AP (A) and lateral (B) radiographs
demonstrating an intra-articular condylar fracture of the
proximal phalanx head. Postoperative AP (C) and
lateral (D) radiographs demonstrate improved articular
congruity after open reduction and internal fixation.
■ Closed Reduction and Pinning of Extra-articular
Proximal Phalanx Shaft Fractures
■ A closed reduction is performed and confirmed on orthogonal radiographs
(TECH FIG 2).
■ The MCP joint is flexed to 90 degrees.
■ A 0.045-in. K-wire is taken freehand and placed at the midpoint of the
metacarpal head in the AP plane and immediately medial or lateral.
■ In my experience, this starting point is more volar than expected.
■ Using a combination of direct feel and fluoroscopy, the K-wire is passed
medial or lateral to the metacarpal head and into contact with the base of the
proximal phalanx.

TECH FIG 2 • AP (A), oblique (B), and lateral (C)
radiographs showing an extra-articular ring finger
proximal phalanx shaft fracture with ulnar deviation and
apex volar deformity. Postoperative AP (D) and lateral
(E) radiographs showing improved alignment after

closed reduction and percutaneous pinning.
■ While holding the reduction, the K-wire is drilled into the phalanx base, across
the fracture sire, and into the head of the proximal phalanx.
■ Placement of the K-wire within the medullary canal (and not through the
phalanx head into the PIP joint) and maintenance of reduction is confirmed
using fluoroscopy.
■ This procedure is repeated to place a second 0.045-in. K-wire on the other side
of the phalanx.
■ The pins are bent and cut outside the skin for later removal.
■ Open Reduction and Internal Fixation of Extra-
articular Proximal Phalanx Shaft Fractures With
Lag Screws
■ A longitudinal incision is made directly over the proximal phalanx. For more
distal fractures, the incision is carried distally in a lazy S over the PIP joint, and
for more proximal fractures, the incision is carried proximally in a lazy S over
the MCP joint.
■ Sharp dissection is carried out down to the extensor mechanism and thick flaps
raised.
■ Fracture exposure can be performed in two ways. I prefer to split the extensor
mechanism longitudinally. I feel that this gives the best exposure of the fracture
and allows the easiest screw placement. The problem with splitting the
extensor tendon is postoperative extensor lag. Alternatively, the interval
between the central extensor tendon and lateral bands can be developed.
■ The fracture site is identified and fracture hematoma cleared.
■ The fracture is provisionally reduced. For oblique fractures, this is often able
to be accomplished with the use of a point-to-point tenaculum clamp or towel
clamp.
■ Be careful to not overcompress with the clamp as this can cause iatrogenic
fracture of the bone.
■ Check rotational alignment.
■ A lag screw is then placed perpendicular to the fracture site. The pilot hole is
drilled first, followed by the gliding hole. The countersink is then used as well

(TECH FIG 3).
■ An additional lag screw is placed perpendicular to the fracture site.
■ Finally, a third screw is placed perpendicular to the other two screws.
■ The extensor mechanism is closed with buried 4-0 Vicryl sutures.
■ Close the skin with nylon sutures.
■ Place the patient in splint with MCP flexed to 60 to 70 degrees, PIP and DIP
fully extended.
TECH FIG 3 • AP (A) and lateral (B) radiographs
demonstrating an extra-articular fracture of the proximal
phalanx shaft. Postoperative AP (C) radiograph
demonstrates improved alignment after open reduction
and internal fixation with a lag screws.
■ Open Reduction and Internal Fixation of Extra-
articular Proximal Phalanx Shaft Fractures With
Mini-Fragment Plates
■ The same approach is used as is described above for lag screw fixation.
■ A 1.2 or 1.7-mm mini-fragment plate is chosen based on the size of the
proximal phalanx.

■ The smallest plate that will offer fracture stability is chosen and hardware
prominence against the extensor mechanism may result in decreased range of
motion.
■ One screw is placed on each side of the fracture and rotational alignment
evaluated (TECH FIG 4A–D).
■ The remaining screws are then placed.
■ The extensor mechanism is closed with buried 4-0 Vicryl sutures.
■ The wound is closed using 4-0 nylon sutures.

TECH FIG 4 • AP (A) and lateral (B) radiographs
demonstrating an extra-articular fracture of the proximal
phalanx base. Postoperative AP (C) and lateral (D)
radiographs demonstrate improved alignment after
open reduction and internal fixation with a mini-
fragment plate and screws.
PEARLS AND PITFALLS
Treatment
■ Perform the least invasive procedure to achieve fracture
stabilization.
Rehabilitation
■ Start early ROM to decrease stiffness.
Starting point
for K-wires
■ The starting point for K-wires is more volar than expected.

Condylar
fractures
■ These fractures tend to have relatively little bone. Be careful to not
overclamp these fractures as they can fall apart. Additionally, do
not try to perform standard lag technique, just place neutralization
screws.
Rotation
■ Be sure to evaluate rotation before final hardware is placed and
after all hardware is in place. Rotational alignment is critical.
POSTOPERATIVE CARE
■ The patient is placed in a plaster splint with the MCP joints flexed to 70
degrees and PIP joints placed in full extension.
■ If stable fixation has been achieved, the postoperative splint is removed at 7 to
10 days and the patient placed into a removable thermoplast splint with the
MCP joints flexed to 70 degrees and the PIP joints left free to allow early
ROM.
■ If the fixation is of questionable stability, the patient is placed into a fiberglass
cast that places the MCP joints to
70 degrees and PIP joints in full extension.
■ Pins are removed at 4 weeks and ROM initiated.
■ At 6 weeks, all immobilization is discontinued and more aggressive ROM is
started.
OUTCOMES
■ Hornbach and Cohen3 reported on 12 extra-articular proximal phalanx
fractures treated with transarticular K-wire fixation.
■ Mean total active motion was 265 degrees and excellent results were
obtained in 10 of 12 fractures.
■ Faruqui et al.4 reported on the outcomes of 50 isolated extra-articular proximal
phalanx fractures that were treated with either transarticular or extra-articular
cross-pinning.
■ The mean total active motion was 201 degrees in the transarticular group and
198 degrees in the extra-articular group.
■ The mean flexion loss at the PIP joint was 27 degrees.
■ Nearly 33% of patients in each group had an extensor lag greater than 15
degrees.
■ Secondary procedures were required in 6/25 patients in the transarticular
group and 2/25 patients in the extra-articular group.
■ Hornbach and Cohen reported on 12 extra-articular proximal phalanx

fractures treated with K-wire fixation at a mean follow-up of 20 months.
COMPLICATIONS
■ Stiffness is a nearly universal complication after treatment of proximal
phalanx fractures.
■ Pin tract infections may occur when percutaneous pins are used.
■ Malunion and nonunion may occur but are uncommon.
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(5):908-915.
2. Gaston RG, Chadderdon C. Phalangeal fractures: displaced/nondisplaced.
Hand Clin. 2012;28(3):395-401.
3. Hornbach EE, Cohen MS. Closed reduction and percutaneous pinning of
fractures of the proximal phalanx. J Hand Surg Br. 2001;26(1):45-49.
4. Faruqui S, Stern PJ, Kiefhaber TR. Percutaneous pinning of fractures in the
proximal third of the proximal phalanx: complications and outcomes. J Hand
Surg [Am]. 2012;37(7):1342-1348.

7
CHAPTERMetacarpal Shaft Fractures
John R. Fowler and Thomas B. Hughes
DEFINITION
■ A metacarpal head fracture is an intra-articular fracture of the metacarpal that
is distal to the metacarpal neck.
■ A boxer’s fracture is a small finger metacarpal neck fracture.
■ Metacarpal fractures constitute 30% of all fractures treated in the emergency
department.
■ Eighty-five percent of these fractures occur in males1
ANATOMY
■ The metacarpals are concave volarly and articulate distally with the base of the
proximal phalanx.
■ The metacarpal base articulates with the distal carpal row.
■ The index and middle metacarpal bases articulate with the trapezoid and
capitate. There is minimal motion at this articulation.2
■ The small and ring finger metacarpal bases articulate with the hamate. This
articulation provides significant flexion and some rotation.2
■ The deep intermetacarpal ligament connects the volar plates of each
metacarpal, preventing significant shortening in the setting of fracture.3
■ Tendon insertions and/or origins may contribute to fracture displacement.
■ FCR inserts on the volar base of the index metacarpal.
■ ECRL inserts on the dorsal base of the index metacarpal.
■ ECRB inserts on the dorsal base of the middle metacarpal.
■ ECU inserts on the dorsal base of the small metacarpal.
■ Interossei arise from the metacarpal shafts.

PATHOGENESIS
■ Metacarpal neck fractures are the result of an axial load applied to a flexed
MCP joint.
■ The most common mechanism of injury is punching a hard object.1
■ Metacarpal shaft fractures can result from axial load, torsion, and/or a direct
blow.3
■ The ring finger metacarpal has the narrowest shaft and therefore has a higher
incidence of shaft fracture from a punching mechanism than do the other
metacarpals.1
■ Metacarpal base/CMC fracture dislocations are almost always the result of
axial loading.
NATURAL HISTORY
■ Pace et al.4 compared 23 patients who underwent a closed reduction and
casting for an isolated small finger metacarpal neck fracture with 43 patients
who did not have a closed reduction.
■ Despite improved angulation after reduction, at final follow-up, there was no
difference in volar angulation between the two groups.
■ Sletten and colleagues5 randomized 85 patients with small finger metacarpal
neck fractures that had more than 30 degrees of volar angulation to either
nonoperative treatment or antegrade bouquet pinning. The authors found no
difference in quickDASH, pain, satisfaction, range of motion, grip strength, or
quality of life between the two groups. However, the operative group had a
higher rate of complications and longer sick leave.
■ Every 2 mm of metacarpal shortening results in 7 degrees of extensor lag.6
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The history often includes an axial load to the hand, usually with the fingers
flexed.
■ The history should include any history of open wounds or punching the mouth
of another person to rule out “fight bite.”
■ “Fight bite” injuries require operative treatment to prevent deep infection.
■ Special attention should be paid to the rotational alignment of the fingers with
flexion.
■ All fingers should roughly point to the distal pole of the scaphoid.
■ Ensure that there is no scissoring.

■ Compare to the contralateral hand.
■ The flexor tendons and collateral ligaments at each joint should be evaluated
to ensure the absence of associated soft tissue injury.
IMAGING
■ AP, oblique, and lateral radiographs of the hand should be obtained.
■ Volar angulation should be measured on the true lateral view as the oblique
view can overestimate true angulation.
■ Consideration to CT scan can be given in cases of metacarpal base fractures to
more accurately determine subluxation and for intra-articular metacarpal head
fractures to more accurately determine the amount of articular step-off and
displacement.
NONOPERATIVE MANAGEMENT
■ Nonoperative treatment is appropriate for the vast majority of metacarpal neck
and shaft fractures.
■ Patients without rotational deformity and/or scissoring and without
pseudoclawing are placed into a hand-based (neck fractures) or forearm-based
(shaft fractures) ulnar gutter splint with the PIP joints left free for early motion
■ The splint is worn full-time for 4 weeks and then discontinued if the fracture
site is no longer tender.
■ Patients who are likely to be noncompliant with splint treatment are placed in
short-arm ulnar gutter casts with the PIP joints left free.
SURGICAL MANAGEMENT
■ Indications3,7
■ Metacarpal neck fractures with more than 10 to 15 degrees of volar
angulation for the index and middle fingers and more than 40 degrees of volar
angulation for the ring and small fingers
■ Metacarpal shaft fractures with more than 10 degrees of volar angulation for
the index and middle fingers and more than 20 degrees of volar angulation for
the ring and small fingers
■ Any rotational deformity or scissoring of the finger with flexion
■ Pseudoclawing
■ Multiple metacarpal fractures
■ Segmental bone loss
■ Open fractures

Preoperative Planning
■ The surgeon should be prepared to perform multiple techniques depending on
specific intraoperative findings.
■ Fractures that may seem treatable with percutaneous pinning are often
deemed to require open reduction internal fixation if an acceptable closed
reduction cannot be obtained or if intraoperative findings are more severe than
previously thought.
■ Consideration should be given to utilization of the technique that results in the
least soft tissue disruption while still restoring alignment and stability.
Positioning
■ The hand is placed on a radiolucent table
■ A forearm tourniquet is used for local-sedation cases and upper arm tourniquet
used for regional block/general cases
Approach
■ Open approaches to the metacarpal are almost always dorsally based.
■ Adjacent metacarpal fractures can be exposed through a single incision
equidistant between the two bones.
■ The periosteum is incised and can sometimes be closed over the fracture if lag
screws or K-wires are used. This is not usually possible if mini-fragment plates
are used.
■ For intra-articular metacarpal fractures, the extensor mechanism is split
longitudinally to access the articular surface and then closed after fixation is
completed.
T E C H N I Q U E S
■ Closed Reduction and Pinning of Metacarpal Neck
Fractures
■ The Jahss technique (TECH FIG 1A) is used to perform a closed reduction of
the metacarpal neck.
■ The reduction is confirmed on the lateral radiograph.

■ While the reduction is held by the assistant, a 0.045-in. K-wire is placed into
the metacarpal head, just ulnar to the extensor mechanism.
■ The K-wire is then advanced across the fracture site and down the metacarpal
shaft.

TECH FIG 1 • A. The Jahss technique. The
metacarpophalangeal and proximal interphalangeal
joints are flexed to 90 degrees and volar to dorsal force
is placed on the proximal phalanx head. This reduces
the volar angulation of the metacarpal neck fracture.
B,C. AP and lateral depictions showing two K-wires
placed longitudinally from the metacarpal head into the
metacarpal shaft on either side of the extensor
mechanism. D. Transverse pinning of a small finger
metacarpal neck fracture to the ring finger metacarpal.
■ A second 0.0450-in. K-wire is then placed into the metacarpal head, just radial
to the extensor mechanism and advanced across the fracture site, into the

metacarpal shaft (TECH FIG 1B,C).
■ The reduction and intramedullary location of the K-wires are confirmed using
orthogonal fluoroscopic views.
■ Alternatively, for border digits, K-wires can be placed perpendicular to the
metacarpal shaft and the fracture can be stabilized to the adjacent metacarpal
(TECH FIG 1D).
■ Open Reduction and Internal Fixation of
Metacarpal Neck or Shaft Fractures with Headless
Compression Screws
■ A 1-cm incision is made dorsally over the metacarpal head (TECH FIG 2A).
■ The extensor tendon is split and dorsal arthrotomy performed (TECH FIG
2B).
■ A 1.1-mm K-wire is placed into the metacarpal head and drilled retrograde to
the level of the fracture (TECH FIG 2C).
■ The K-wire should be in the dorsal third of the metacarpal head on the lateral
and not through the articular portion of the cartilage.
■ Consider using a longer K-wire so that you are able to pass the screw and not
lose the K-wire into the metacarpal shaft.
■ The fracture is then reduced and K-wire driven across the fracture site.
Intramedullary location of the K-wire and adequate reduction is confirmed on
orthogonal fluoroscopic views.
■ A cannulated headless compression screw is then placed over the K-wire
(TECH FIG 2D,E).
■ We recommend a 3.0- to 3.5-mm screw with the exception of the ring finger
because of the narrow diameter of its shaft. For the ring finger, we use a 2.0-
or 2.5-mm screw.
• Measure the width of the intramedullary canal as its isthmus prior to surgery
to confirm that it is wide enough (at least 2 mm) to accept an implant.
■ The screw is inserted beneath the articular surface.
■ Attempt to center the screw on the fracture site to maximize compression,
although this is difficult for metacarpal neck fractures given their proximity
to the joint.
■ The extensor split is closed with buried 4-0 Vicryl followed by 4-0 nylon for

the skin.

TECH FIG 2 • A. Dorsal skin incision and exposure of

extensor mechanism. B. The extensor mechanism is
splint and the metacarpal head exposed. C. A K-wire is
placed in the dorsal third of the metacarpal head and
driven retrograde across the fracture site after reduction
has been performed. D,E. AP and lateral radiographs
demonstrating a headless compression screw placed
across the fracture site and within the metacarpal shaft.
■ Closed Reduction and Pinning of Metacarpal Shaft
Fractures (Bouquet Technique)8
■ A closed reduction is performed and confirmed on orthogonal radiographs. If
an adequate closed reduction cannot be obtained, this technique is abandoned.
■ A 2-cm longitudinal incision is made centered on the base of the metacarpal.
■ Dissection is carried out down to bone, taking care to protect the extensor
tendons.
■ A small hole is made on the ulnar aspect of the metacarpal base (TECH FIG
3A,B), extra-articularly, taking care to not penetrate the radial cortex. This can
be done using an awl or a small drill bit.
■ Three round-tip 0.035-in. K-wires are gently bent (TECH FIG 3C).
■ The fracture is reduced, and each K-wire is placed into the intramedullary
canal and drilled across the fracture site and into the metacarpal head.
■ The K-wires are placed in divergent directions to form a “bouquet” in the
metacarpal head. It is often necessary to get the K-wires in the canal and across
the fracture site, then use a needle driver to rotate the pins into divergent
directions (TECH FIG 3D,E)
■ Reduction is confirmed on fluoroscopy.
■ The pins are cut outside the metacarpal base, taking care to leave enough K-
wire protruding for easy removal.
■ The skin is closed with nylon suture.

TECH FIG 3 • A. A radiolucent tool is used to locate the
entry site for the pins, and the skin is marked with a
marking pen. B. A 1- to 2-cm incision is made and
dissection carried out down to bone. A 2.0-mm drill bit

or curette is used to make a hole in the base of the
metacarpal taking care to remain well extra-articular. C.
The pins are bent with a gentle curve at the tip. D,E.
Three pins are then placed into the intramedullary
canal, and a needle driver is used to rotate them into
divergent directions after being placed across the
fracture site.
■ Open Reduction and Internal Fixation of
Metacarpal Shaft Fractures With Lag Screws
■ Open reduction and internal fixation with lag screws requires an oblique
fracture line that is at least twice the width of the metacarpal shaft.
■ For a single metacarpal fracture, the incision is placed directly over the
metacarpal. For multiple adjacent fractures, the incision is placed midway
between the metacarpals to allow access to both (TECH FIG 4A).
■ Dissection is carried out bluntly down to the level of the extensor tendons
(TECH FIG 4B).
■ The tendon is retracted and periosteum incised over the metacarpal.
■ The fracture is exposed and debrided (TECH FIG 4C).
■ The fracture is provisionally reduced. For oblique fractures this can often be
accomplished with the use of a point-to-point tenaculum clamp or towel clamp
(TECH FIG 4D).
■ Care must be taken not to overcompress with the clamp, as this can cause
iatrogenic fracture of the metacarpal.
■ Rotational alignment is checked (TECH FIG 4E).
■ A lag screw is then placed perpendicular to the fracture site. The pilot hole is
drilled first, followed by the gliding hole. The countersink is then used as well.
■ An additional lag screw is placed perpendicular to the fracture site as well.
■ Finally, a third screw is placed perpendicular to the other two screw. (TECH
FIG 4F).
■ Close periosteum over the fracture site if possible.
■ Close skin with nylon sutures.
■ Place the patient in splint with MCP flexed to 60 to 70 degrees, PIP and DIP
fully extended.

TECH FIG 4 • A. A longitudinal incision is made over
the affected metacarpal shaft. B. Blunt dissection is
carried out down to the extensor mechanism. C. The
extensor mechanism is retracted and fracture site
exposed. D. The fracture site is debrided of soft tissue
and callus and provisionally reduced. E. Rotational
alignment is confirmed prior to placing screws. F. Lag
screws are placed and orthogonal radiographs obtained
to confirm anatomic reduction.

■ Open Reduction and Internal Fixation of
Metacarpal Shaft Fractures With Mini-Fragment
Plates
■ Open reduction internal fixation with mini-fragment plates and screws may be
indicated for transverse fractures or fractures that cannot be adequately reduced
and stabilized using percutaneous techniques (TECH FIG 5A,B)
■ For a single metacarpal fracture, the incision is placed directly over the
metacarpal (TECH FIG 5C). For multiple adjacent fractures, the incision is
placed midway between the metacarpals to allow access to both.
■ Dissection is carried out bluntly down to the level of the extensor tendons
(TECH FIG 5D).
■ The tendon is retracted and periosteum incised over the metacarpal.
■ The fracture is exposed and debrided (TECH FIG 5E).
■ The fracture is provisionally reduced (TECH FIG 5F).
■ Sometimes it is easier to fix the plate to one side of the fracture and then
reduce the fracture to the plate. This is especially true of transverse fracture
that are difficult to hold reduced using fracture clamps.
■ Place one screw proximally and distally (TECH FIG 5G).
■ Check rotation of the finger (TECH FIG 5H) and radiographs.
■ If satisfied with alignment and rotation, fill remaining screw holes (TECH
FIG 5I–K).
■ Close periosteum over plate if possible.
■ Close skin with nylon sutures.
■ Place the patient in splint with MCP flexed to 60 to 70 degrees, PIP and DIP
fully extended.

(Trang không có chữ)

(Trang không có chữ)

TECH FIG 5 • A,B. AP and lateral radiographs
demonstrating displaced metacarpal shaft fractures of
the small and ring fingers. C. A longitudinal incision is
placed over the metacarpal shaft of the affected
metacarpal. D. Blunt dissection is carried out down to
the extensor tendon. E. The tendon is retracted and
periosteum incised. The fracture is exposed and
debrided. F. The fracture is preliminarily reduced. G.
The mini-fragment plate is affixed to the bone
proximally and distally with one screw each. H.
Rotational alignment is evaluated prior to placing the
remaining screws. I. The remaining screws are placed
and orthogonal radiographs scrutinized. J,K.
Postoperative AP and lateral radiographs after plate
fixation.
PEARLS AND PITFALLS
Indications
■ Surgical treatment of metacarpal shaft fractures is indicated
for rotational malalignment and/or volar flexion of more than
10 degrees for the index and middle fingers and more than 20
degrees for the ring and small fingers.
Rotation
■ Once K-wires or screws have been placed, be sure to check
rotation by flexing the fingers prior to definitive fixation
and/or closure.
Open reduction
and internal
fixation with
mini-fragment
plates
■ Do not waste time trying to achieve a perfect reduction before
plate placement; sometimes it is easier to affix the plate to one
side of the fracture and reduce the other side to the plate. Try
to minimize soft tissue stripping.
Therapy
■ If stable fixation, early ROM can be initiated at 10–14 d.

POSTOPERATIVE CARE
■ Patients are immobilized in a nonremovable postoperative splint for the first
10 to 14 days. This splint flexes the MCP to 60 to 70 degrees and ideally leaves
the PIP and DIP free for early motion.
■ Sutures are removed at 10 to 14 days, and a forearm-based orthoplast splint is
fabricated with the MCP joint in 60 to 70 degrees of flexion and PIP and DIP
free for early motion.
■ At 6 weeks, the splint is discontinued and therapy continued to regain full
ROM.
OUTCOMES
■ Ruchelsman et al.7 reported on 20 patients at minimum 3-month follow-up
who underwent limited-open retrograde headless screw fixation of metacarpal
neck and shaft fractures. The union rate at 6 weeks was 100%, and all patients
regained full composite fist by 3 months and extensor lag resolved by 3 weeks.
Mean grip strength improved to 105% of the contralateral side.
■ Doarn and colleagues9 reviewed nine patients with nine metacarpal fractures
treated with retrograde headless screw fixation at mean follow-up of 36 weeks.
The union rate was 100% at a mean of 49 days, and mean return to work was 6
weeks. Mean grip strength returned to 95% of the uninjured hand.
■ Kim and Kim10 randomized 46 patients with metacarpal neck fractures to
antegrade or retrograde intramedullary pinning. The authors found similar final
radiographic alignment, but improved range of motion and DASH at 3 months
in the antegrade pinning group.
COMPLICATIONS
■ The complication rate depends greatly on the mechanism of injury and the
amount of contamination in open injuries.
■ Infection
■ The deep infection rate for closed metacarpal fractures treated operatively is
0.5% compared to 2% to 11% for operative treatment of open fractures.11
■ Malrotation
■ Rotational deformity can significantly affect hand function.
■ Malrotation of 5 degrees results in up to 1.5 cm of finger overlap with
flexion.11
■ Malunion

■ Volar angulation of the fracture or shortening can result in an extensor lag at
the MCP joint.
• For every 2 mm of shortening, there is 7 degrees of extensor lag.6
• Due to natural hyperextension at the MCP joint, up to 6 mm of shortening
may be acceptable in most patients.11
■ The rate of nonunion approaches 6% in some series after ORIF.12
REFERENCES
1. Soong M, Got C, Katarincic J. Ring and little finger metacarpal fractures:
mechanisms, locations, and radiographic parameters. J Hand Surg [Am].
2010;35(8):1256-1259.
2. Kozin SH, Thoder JJ, Lieberman G. Operative treatment of metacarpal and
phalangeal shaft fractures. J Am Acad Orthop Surg. 2000;8(2):111-121.
3. Diaz-Garcia R, Waljee JF. Current management of metacarpal fractures. Hand
Clin. 2013;29(4):507-518.
4. Pace GI, Gendelberg D, Taylor KF. The Effect of closed reduction of small
finger metacarpal neck fractures on the ultimate angular deformity. J Hand
Surg [Am]. 2015;40(8):1582-1585.
5. Sletten IN, Hellund JC, Olsen B, et al. Conservative treatment has comparable
outcome with bouquet pinning of little finger metacarpal neck fractures: a
multicentre randomized controlled study of 85 patients. J Hand Surg Eur Vol.
2015;40(1):76-83.
6. Strauch RJ, Rosenwasser MP, Lunt JG. Metacarpal shaft fractures: the effect
of shortening on the extensor tendon mechanism. J Hand Surg [Am].
1998;23(3):519-523.
7. Ruchelsman DE, Puri S, Feinberg-Zadek N, et al. Clinical outcomes of
limited-open retrograde intramedullary headless screw fixation of metacarpal
fractures. J Hand Surg [Am]. 2014;39(12):2390-2395.
8. Foucher G. “Bouquet” osteosynthesis in metacarpal neck fractures: a series of
66 patients. J Hand Surg [Am]. 1995;20(3 Pt 2):S86-S90.
9. Doarn MC, Nydick JA, Williams BD, Garcia MJ. Retrograde headless
intramedullary screw fixation for displaced fifth metacarpal neck and shaft
fractures: short term results. Hand (N Y). 2015;10(2):314-318.
10. Kim JK, Kim DJ. Antegrade intramedullary pinning versus retrograde
intramedullary pinning for displaced fifth metacarpal neck fractures. Clin
Orthop Relat Res. 2015;473(5):1747-1754.
11. Balaram AK, Bednar MS. Complications after the fractures of metacarpal and

phalanges. Hand Clin. 2010;26(2):169-177.
12. Page SM, Stern PJ. Complications and range of motion following plate
fixation of metacarpal and phalangeal fractures. J Hand Surg [Am].
1998;23(5):827-832.

8
CHAPTER
Open Reduction for
Carpometacarpal Joint
Dislocation
John R. Fowler and Robert A. Kaufmann
DEFINITION
■ Dislocation of the carpometacarpal (CMC) joint of the fingers may be simple
(ligamentous disruption without fracture) or complex (associated with a
fracture of the distal carpal row and/or metacarpal base).
■ These injuries most commonly involve a dorsal direction of instability with
subluxation or dislocation of the metacarpal base occurring relative to the
carpal bones. Although rare, volar dislocations have been reported as well.
ANATOMY
■ General
■ The index and middle finger CMC joints are more constrained than the small
and ring finger CMC joints.
• The index and long finger CMC joints have 11 and 7 degrees of flexion
extension, respectively.1
• The ring and small CMC joints have 20 and 44 degrees of flexion extension,
respectively.1
■ This leads to increased incidence of small and ring finger CMC joint
dislocations compared to index and middle CMC dislocations.
■ Skeletal anatomy
■ The base of the index metacarpal is concave with radial and ulnar condyles
that surround the trapezoid. The ulnar condyle also articulates with the long
metacarpal and capitate, and the radial condyle has an articulation with the
trapezium.2
■ The concave long metacarpal base articulates with the convex capitate and

has a dorsoradial process that increases stability.2
■ The ring finger metacarpal base is locked by its articulations with the
metacarpal bases of the middle and small finger and the hamate.2
■ The small finger metacarpal base has an ulnar slope and articulates with the
hamate.2
■ Viegas et al.3 classified the shape of the ring finger metacarpal base. The
description is based on the number and positions of facets. The clinical
relevance of this classification system is unclear.
■ Ligamentous anatomy (FIG 1)
■ Conflicting descriptions exist in the literature with some authors reporting up
to six dorsal and six volar ligaments to each CMC joint4 and others reporting
only one dorsal CMC ligament.5
■ Nakamura and colleagues6 dissected 80 cadaver wrists and noted that the
anatomy is different depending on which CMC is being studied.
• The ring and small finger CMC joint have two distinct dorsal ligaments.
• The index and long finger CMC joints typically have three distinct dorsal
ligaments.
• An intra-articular ligament exists between the long/ring finger metacarpal
base and the capitate/hamate. This ligament resists dorsal dislocation even if
the other volar and dorsal ligaments are cut.
■ Each CMC joint also has volar ligaments that resist dorsal dislocation.
• The index and long CMC joints have two deep capsular ligaments that
connect the metacarpal bases to the trapezium and two superficial ligaments
that connect the metacarpal bases to the capitate.
PATHOGENESIS
■ The most common mechanism of injury is punching a hard object with a
closed fist.
■ Axial mechanical loading through a flexed MCP joint generates a rotational
moment that causes a dorsally directed force on the metacarpal base.
■ Yoshida and colleagues7 found that capitate and hamate fractures were the
most common fractures associated with ring and small finger CMC
dislocations.

FIG 1 • Dorsal ligaments of the carpometacarpal joints.
■ The ring and small finger CMC joints are more susceptible to injury than the
index and long finger CMC joints due to increased mobility.8
NATURAL HISTORY
■ Untreated CMC dislocations and fracture dislocations result in noticeable hand
deformity, pain, limited range of motion, and decreased grip strength.9
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Most patients will present after punching a hard object with a closed fist. Other
mechanisms can include an axial load on flexed metacarpals from a fall or
motor vehicle accident.
■ A thorough skin examination should be performed to rule out other injuries
associated with punching, including “fight bite,” which would require urgent

surgical debridement.
■ Assessment of the soft tissues is focused on identifying skin disruption and
extensor tendon damage.
■ There is typically significant swelling, ecchymosis, and the inability to make a
composite fist.
■ Rotational malalignment is uncommon.
IMAGING
■ Standard AP, lateral, and oblique radiographs are obtained (FIG 2).
■ When a PA radiograph is taken in neutral, the normal CMC joints should have
parallel articular surfaces, symmetric width between all CMC joint spaces (1–2
mm), and no overlapping joint surfaces.10
■ Close attention must be paid to the lateral and oblique radiograph to evaluate
for dorsal subluxation and/or dislocation of the metacarpal on the distal carpal
row.
■ On a true lateral radiograph the normal angle between the long axis of the
index and small metacarpals should be approximately 10 degrees. Angles near
40 degrees suggest dislocation.11 Comparison to the contralateral side can be
useful.
■ An oblique radiograph with the forearm pronated 30 to 45 degrees from the PA
will allow optimal visualization of the small and ring finger metacarpal base
articulations with the distal carpal row.11–13 Occasionally, a 15-degree
pronation oblique is beneficial to fully assess the injury to the fourth and fifth
CMC joints.14
■ In unclear cases, consideration should be given to CT scan to further evaluate
the CMC joint.15
DIFFERENTIAL DIAGNOSIS
■ Metacarpal fracture
■ Contusion
■ CMC dislocation
■ CMC fracture dislocation
NONOPERATIVE MANAGEMENT
■ Nonoperative treatment may be considered if an adequate closed reduction can
be obtained and remains stable. Close follow-up with weekly serial radiographs
is recommended to ensure maintenance of the closed reduction.

■ An ulnar gutter cast for fourth and fifth CMC injuries and a radial gutter cast
for second and third CMC injuries are recommended. It is imperative that the
cast prevent CMC subluxation through a dorsal mold. Keeping the MCP joint
in no more than 40 to 50 degrees of flexion should prevent recurrence of dorsal
subluxation at the CMC joints.
SURGICAL MANAGEMENT
Preoperative Planning
■ The surgeon should be prepared to perform both closed and open reduction as
needed to obtain a concentric reduction of the CMC joints.
■ General or regional anesthesia is obtained.
FIG 2 • PA (A), oblique (B), and lateral (C) radiographs
demonstrating dorsal dislocation of the small and ring
finger CMC joints.
■ A drill and multiple K-wires should be available. A mini-fragment set is
required to treat carpal fractures that may require open reduction and internal
fixation.
■ Intraoperative fluoroscopy is used to confirm adequate reduction and to direct
K-wire placement.
Positioning
■ The patient is placed in the supine position with the forearm pronated on a
radiolucent table.
■ The surgeon typically sits at the head of the bed to facilitate placement of K-

wires.
Approach
■ The approach to the CMC joint is dorsal and centered directly over the CMC
joint. For multiple CMC dislocations, the incision can be placed between the
two CMC joints.
■ If all four CMC joints are dislocated and open reduction is required, a single
incision can be placed over the middle finger metacarpal and thick flaps raised
to visualize all four CMC joints.
■ The dorsal ulnar and dorsal radial sensory nerves are fully visualized and freed
up so that they can be gently retracted during the procedure.
T E C H N I Q U E S
■ Closed Reduction and Percutaneous Pinning
■ A closed reduction is attempted with longitudinal traction on the affected
metacarpal and dorsal to volar direct pressure on the metacarpal bases (TECH
FIG 1A,B).
■ The reduction is confirmed on AP, lateral, and oblique fluoroscopy images.
■ While holding direct dorsal to volar pressure on the metacarpal bases, a 0.045-
in. K-wire is drilled from the small finger metacarpal into the ring finger
metacarpal, 1 to 2 cm distal to the CMC joint (TECH FIG 1C).
■ Familiarity with the location of the dorsal ulnar sensory nerve is imperative
to avoid its injury. As a principle, avoiding the most dorsal ulnar region of
the fifth metacarpal shaft will avoid injury to this nerve.
■ If the ring finger metacarpal base is also involved, the K-wire is also drilled
into the middle finger metacarpal shaft.
■ A second 0.045-in. K-wire is placed in similar fashion, 1 to 2 cm distal to the
first K-wire.
■ The second K-wire prevents rotation around the first K-wire.
■ A third K-wire may be placed from the small finger metacarpal base into the
hamate for added subluxation resistance.
■ Fluoroscopy confirms maintained reduction of the CMC joints (TECH FIG
1D–F).

■ The pins are cut below the skin.
■ A well-padded volar splint is placed.
TECH FIG 1 • A. Photograph of the same injury in FIG 2
demonstrating the dorsal deformity associated with the
dorsal dislocation of the metacarpal bases. B.
Longitudinal traction is placed on the affected fingers
and direct dorsal pressure is placed on the metacarpal
base to reduced the dislocation. C,D. The pins in place

after closed reduction and percutaneous pinning. E–G.
AP, oblique, and lateral radiographs, respectively,
showing placement of the percutaneous pins and
reduction of the CMC bases (compare with FIG 2). Note
that on the lateral view (E), the metacarpals all line up
and there is no dorsal subluxation of the small and ring
finger metacarpal bases.
■ Open Reduction and Pinning With or Without
Internal Fixation of Carpal Fractures
■ A closed reduction is attempted with longitudinal traction on the affected
metacarpal and dorsal to volar direct pressure on the metacarpal bases.
■ If an adequate closed reduction cannot be maintained, an open reduction is
performed.
■ A longitudinal incision is made in between the small and ring finger
metacarpal bases.
■ Blunt dissection is carried out to the extensor tendons. The interval between
the extensor digitorum communis to the ring finger and extensor digiti minimi
is developed.
■ The capsule over the CMC joints is incised longitudinally and sharply elevated
radially and laterally to allow visualization of the joint.
■ Fibrosis and/or hematoma is cleared from the joint and a reduction
performed.
■ While holding direct dorsal to volar pressure on the metacarpal bases, a 0.045-
in. K-wire is drilled from the small finger metacarpal into the ring finger
metacarpal, 1 to 2 cm distal to the CMC joint.
■ Similar to the closed reduction pinning algorithm, pins are placed into the
middle finger metacarpal shaft when the ring CMC joint is also injured.
■ If the ring finger metacarpal base is also involved, the K-wire is also drilled
into the middle finger metacarpal shaft.
■ A second 0.045-in. K-wire is placed in similar fashion, 1 to 2 cm distal to the
first K-wire.
■ The second K-wire prevents rotation around the first K-wire.
■ An additional K-wire may be placed from the small finger metacarpal base

into the hamate for added stability.
■ If there is a sizeable fracture of the dorsal lip of the hamate, this can be
addressed using 1.2- or 1.5-mm mini-fragment screws (TECH FIG 2).
■ Ensure that the drill does not plunge through the volar cortex of the hamate
given the close proximity of the ulnar nerve motor branch to the hook of the
hamate.
■ Fluoroscopy confirms maintained reduction of the CMC joints.
■ The pins are cut below the skin.
■ The CMC capsule is closed with absorbable suture. The skin is closed with 4-0
nylon.
■ A well-padded ulnar gutter splint is placed.
TECH FIG 2 • A. Fracture of the dorsal lip of the
hamate. B. After internal fixation of the hamate with a
mini-fragment plate. For small fragments, mini-fragment
screws alone can be used.
PEARLS AND PITFALLS
Radiographs
■ Scrutinize the lateral and oblique radiographs to evaluate for
dorsal subluxation/dislocation of the metacarpal base. Obtain a
CT scan if necessary.
Preoperative
workup
■ Have a low threshold to obtain a CT scan if necessary.

Fixation
■ At least two K-wires are needed to maintain joint alignment.
Ensure that pins gain secure purchase in uninjured metacarpals in
order to transmit forces away from zone of injury. Consider third
pin directed obliquely from metacarpal into carpal bone to
improve biomechanical rigidity of fixation.
K-wires
■ Bury K-wires under the skin for later removal at 10–12 wk. A
longer period of fixation is required to allow healing of the dorsal
ligaments.
Postoperative
immobilization
■ Cast immobilization is recommended for nonoperatively treated
injuries.
■ Immobilize unreliable postoperative patients in a cast after
sutures are removed.
POSTOPERATIVE CARE
■ Patients are placed in an ulnar gutter splint with the MCP joints free.
■ Early finger motion is started to minimize stiffness.
■ The postoperative splint is removed at 2 weeks and the patient is placed into
either a removable thermoplast splint or a short-arm cast. This decision is
based on the perceived reliability of the patient. Less reliable patients are
placed into casts.
■ Radiographs are obtained at 2, 6, and 10 weeks to ensure no further
subluxation of the metacarpal base and to evaluate for healing of any carpal
fractures that may have been present.
■ Buried pins are typically removed in the operating room under sedation and
local anesthetic at 10 to 12 weeks.
OUTCOMES
■ Zhang et al.9 reviewed 20 fracture dislocations of the small and ring finger
CMC joints at mean follow-up of 1 year.
■ Mean Michigan Hand Questionnaire score was 98.
■ Patients obtained similar range of motion and grip strength to the
contralateral hand.
■ Patients treated without surgery had worse mean grip strength (31 kg vs 45
kg) and worse Michigan Hand Questionnaire score (72 vs 98).
■ Gehrmann and colleagues8 reported on 16 fracture dislocations of the small
and ring finger CMC joints and 23 fracture dislocations of the small finger

CMC joint treated with either closed reduction and pinning or open reduction
and internal fixation at mean follow-up of 13 months.
■ Mean DASH score at final follow-up was 6.0 for small and ring finger
dislocations and 7.2 for small finger dislocations.
■ Grip strength was 16% less than the uninjured side.
■ There were no cases of recurrent dislocation or subluxation.
COMPLICATIONS
■ Post-traumatic arthritis may occur despite the surgeon’s best effort. This is
secondary to cartilage injury during the dislocation event.
■ Finger stiffness is common secondary to swelling and pain.
■ Recurrent dorsal subluxation/dislocation is uncommon but has been reported.
REFERENCES
1. El-Shennawy M, Nakamura K, Patterson RM, Viegas SF. Three-dimensional
kinematic analysis of the second through fifth carpometacarpal joints. J Hand
Surg [Am]. 2001;26(6):1030-1035.
2. Bushnell BD, Draeger RW, Crosby CG, Bynum DK. Management of intra-
articular metacarpal base fractures of the second through fifth metacarpals. J
Hand Surg [Am]. 2008;33(4):573-583.
3. Viegas SF, Crossley M, Marzke M, Wullstein K. The fourth carpometacarpal
joint. J Hand Surg [Am]. 1991;16(3):525-533.
4. Gurland M. Carpometacarpal joint injuries of the fingers. Hand Clin.
1992;8(4):733-744.
5. Harwin SF, Fox JM, Sedlin ED. Volar dislocation of the bases of the second
and third metacarpals: a case report. J Bone Joint Surg Am. 1975;57(6):849-
851.
6. Nakamura K, Patterson RM, Viegas SF. The ligament and skeletal anatomy of
the second through fifth carpometacarpal joints and adjacent structures. J Hand
Surg [Am]. 2001;26(6):1016-1029.
7. Yoshida R, Shah MA, Patterson RM, et al. Anatomy and pathomechanics of
ring and small finger carpometacarpal joint injuries. J Hand Surg [Am].
2003;28(6):1035-1043.
8. Gehrmann SV, Kaufmann RA, Grassmann JP, et al. Fracture-dislocations of
the carpometacarpal joints of the ring and little finger. J Hand Surg Eur Vol.
2015;40(1):84-87.
9. Zhang C, Wang H, Liang C, et al. The Effect of timing on the treatment and

outcome of combined fourth and fifth carpometacarpal fracture dislocations. J
Hand Surg [Am]. 2015;40(11):2169-2175, e2161.
10. Fisher MR, Rogers LF, Hendrix RW. Systematic approach to identifying
fourth and fifth carpometacarpal joint dislocations. AJR Am J Roentgenol.
1983;140(2):319-324.
11. Parkinson RW, Paton RW. Carpometacarpal dislocation: an aid to diagnosis.
Injury. 1992;23(3):187-188.
12. Liaw Y, Kalnins G, Kirsh G, Meakin I. Combined fourth and fifth metacarpal
fracture and fifth carpometacarpal joint dislocation. J Hand Surg Br.
1995;20(2):249-252.
13. Cain JE Jr, Shepler TR, Wilson MR. Hamatometacarpal fracture-dislocation:
classification and treatment. J Hand Surg [Am]. 1987;12(5 Pt 1):762-767.
14. Bora FW Jr, Didizian NH. The treatment of injuries to the carpometacarpal
joint of the little finger. J Bone Joint Surg Am. 1974;56(7):1459-1463.
15. Pullen C, Richardson M, McCullough K, Jarvis R. Injuries to the ulnar
carpometacarpal region: are they being underdiagnosed? Aust N Z J Surg.
1995;65(4):257-261.

9
CHAPTER
Reconstruction of Acute and
Chronic Ulnar Collateral
Ligament Injuries of the
Thumb
John R. Fowler and Robert A. Kaufmann
DEFINITION
■ An acute tear of the ulnar collateral ligament (UCL) is defined as an injury that
is less than 12 weeks. Acute tears can often be repaired.
■ A chronic tear is an injury that is older than 12 weeks. Chronically injured
UCLs are often in need of reconstruction.
■ The ligament integrity at the time of surgery is the primary determinant of
whether a repair or a reconstruction may be performed. Chronic tears,
especially in younger patients, can often still be repaired with excellent results.
Acutely injured UCLs, particularly Stener lesions, may not be amenable to a
repair and might benefit from a reconstruction effort.
ANATOMY
■ The thumb UCL has proper and accessory components.
■ The proper UCL is tight in 20 to 30 degrees of flexion.
■ The origin is from the metacarpal with the center of insertion 4.2 mm from
the dorsum of the metacarpal and 5.3 mm proximal to the articular surface
(FIG 1).
■ The insertion is on the proximal phalanx with a center of insertion 2.8 mm
from the volar surface and 3.4 mm distal to the articular surface.1
■ The accessory collateral ligament is tight in full extension.
■ The accessory collateral ligament is volar to the proper and has an origin on
the metacarpal and inserts into the volar plate and proximal phalanx base.

FIG 1 • The anatomy of the ulnar collateral ligament of
the thumb metacarpophalangeal (MCP) joint. A. In
extension, the accessory collateral ligament is taut. B.
In flexion, the proper collateral ligament is taut.
■ The adductor pollicis longus inserts through its aponeurosis into the extensor
hood over the metacarpophalangeal (MCP) joint.
■ The dorsal capsule of the MCP joint acts as a secondary stabilizer in flexion.2
■ The extensor pollicis longus, extensor pollicis brevis, and flexor pollicis
longus provide dynamic joint stability.
PATHOGENESIS
■ A forceful valgus stress to the thumb results in disruption of the UCL.
■ The ligament may tear and yet not retract substantially from its insertion into
the proximal phalanx.
■ A “Stener lesion” is created when the stump of a completely ruptured UCL
retracts proximally and then the adductor aponeurosis becomes interposed
between the UCL and its insertion on the proximal phalanx3 (FIG 2).
■ Chronic repetitive valgus stress may result in UCL laxity. Antecedent trauma
is likely the sentinel event that caused ligament damage, whose healing was
interrupted through chronic reaggravation leading to laxity of the UCL