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Surgical management may be considered for acute and chronic mallet lesions in patients who have failed nonsurgical treatment, are unable to work with the splint in position, or have a fr

Mallet Finger

Abstract

Mallet finger involves loss of continuity of the extensor tendon over the distal interphalangeal joint This common hand injury results in a flexion deformity of the distal finger joint and may lead

to an imbalance between flexion and extension forces more proximally in the digit Mallet injuries can be classified into four types, based on skin integrity and the presence or absence of bony involvement Although various treatment protocols have been proposed, splinting of the distal interphalangeal joint for 6 to 8 weeks has yielded good results while minimizing morbidity in the majority of patients Surgical management may be considered for acute and chronic mallet lesions in patients who have failed nonsurgical treatment, are unable to work with the splint in position, or have a fracture involving more than one third of the joint surface

Fingertip injuries are among the most common traumatic prob-lems encountered by hand surgeons

One such injury, which involves dis-ruption of the extensor mechanism

at the level of the distal interpha-langeal (DIP) joint, is commonly re-ferred to as a mallet, baseball, or drop finger.1,2The term mallet finger originated during the late nineteenth century, in reference to a frequently seen sports-related flexion

deformi-ty of the fingertip.3 The injury is now known to occur in association with any activity leading to forced flexion of the DIP joint

Recognition and diagnosis of a mallet finger are relatively straight-forward Treatment requires careful attention to detail by the surgeon and diligent patient compliance to restore function and avoid complica-tions Knowledge of the complex anatomy of the extensor mechanism

of the finger is essential, as is a thor-ough understanding of how a disrup-tion at the DIP joint level can upset the delicate balance of extension and

flexion forces more proximally Al-though most mallet injuries can be successfully managed nonsurgically, surgery is occasionally

recommend-ed for treatment of either an acute or

a chronic mallet finger or for salvage

of failed prior treatment

Epidemiology

Mallet finger injuries usually occur

in the work environment or during sports participation.2The most fre-quently involved digits are the long, ring, and small fingers of the domi-nant hand.1The lesion is often seen

in young to middle-aged males; women with this injury tend to be older Although most mallet fingers are caused by a traumatic event, Jones and Peterson4found an unusu-ally high incidence in a three-generation family, with 85% of the lesions developing spontaneously or after minimal trauma The authors proposed a possible genetic predispo-sition toward mallet finger

deformi-ty in certain individuals

Anup A Bendre, MD,

Brian J Hartigan, MD, and

David M Kalainov, MD

Dr Bendre is Orthopaedic Surgeon,

OAD Orthopaedics, Warrenville, IL.

Dr Hartigan is Assistant Professor of

Clinical Orthopaedic Surgery,

Department of Orthopaedic Surgery,

Northwestern University, Feinberg

School of Medicine, Northwestern

Center for Orthopedics, Chicago, IL.

Dr Kalainov is Assistant Professor of

Clinical Orthopaedic Surgery,

Department of Orthopaedic Surgery,

Northwestern University, Feinberg

School of Medicine, Northwestern

Center for Orthopedics.

None of the following authors or the

departments with which they are

affiliated has received anything of value

from or owns stock in a commercial

company or institution related directly or

indirectly to the subject of this article:

Dr Bendre, Dr Hartigan, and Dr.

Kalainov.

Reprint requests: Dr Bendre, OAD

Orthopaedics, 27650 Ferry Road,

Warrenville, IL 60555-3845.

J Am Acad Orthop Surg

2005;13:336-344

Copyright 2005 by the American

Academy of Orthopaedic Surgeons.

The anatomy of the extensor

ten-don of the finger has been well

described1,2,5-7(Fig 1) The extrinsic

extensor tendon originates in the

forearm and courses over the finger

metacarpophalangeal (MCP) joint

The extrinsic extensor tendon has an

indirect attachment to the proximal

phalanx, such that the primary

ex-tensor force across the MCP joint is

transmitted through the sagittal

band connections to the volar plate

The extrinsic tendon continues

dis-tally and trifurcates over the

proxi-mal phalanx The central

continua-tion of the extensor tendon (ie, the

central slip) attaches to the dorsal

base of the middle phalanx, exerting

an extensor force across the

proxi-mal interphalangeal (PIP) joint

The interosseous and lumbrical

muscles provide the intrinsic

contri-bution to the extensor mechanism

These muscle-tendon units form a lateral band on each side of the

dig-it, passing volar to the MCP joint

The lateral bands join with the

later-al slips of the extrinsic extensor ten-don at the level of the PIP joint to form the conjoined lateral bands

The two conjoined lateral bands then converge dorsally and insert at the base of the distal phalanx as the terminal extensor tendon

The other components of the ex-tensor apparatus stabilize the exten-sor hood and coordinate joint move-ment The triangular ligament is a thin tissue connecting the conjoined lateral bands over the middle pha-lanx This structure prevents separa-tion and volar migrasepara-tion of the

later-al bands when the PIP joint is flexed

The transverse retinacular ligaments originate from each side of the PIP joint volar plate, inserting dorsally into the adjacent conjoined lateral band These ligaments stabilize and

limit dorsal migration of the lateral bands during PIP joint extension The oblique retinacular ligaments arise from the flexor tendon sheath and volar aspect of the proximal pha-lanx They course distally to insert onto the dorsal base of the distal phalanx with the terminal extensor tendon, thus linking and coordinat-ing PIP and DIP joint motion

Mechanism of Injury and Pathoanatomy

Mallet finger most commonly is caused by sudden forced flexion of the extended fingertip, resulting in either stretching or tearing of the ex-tensor tendon substance or avulsion

of the tendon insertion from the dor-sum of the distal phalanx, with or without a fragment of bone Open injuries are caused by a laceration, crush, or deep abrasion A less fre-quent mechanism of injury involves

Figure 1

Finger extensor mechanism anatomy A, Lateral view B, Dorsal view DIP = distal interphalangeal joint, MCP =

metacarpopha-langeal joint, ORL = oblique retinacular ligament, PIP = proximal interphametacarpopha-langeal joint, TRL = transverse retinacular ligament

(Adapted with permission from Coons MS, Green SM: Boutonniere deformity Hand Clin 1995;11:387-402.)

forced hyperextension of the DIP

joint with a resultant fracture at the

dorsal base of the distal phalanx.2

The functional anatomy of the

finger represents a well-balanced

system between intrinsic and

extrin-sic tendons, and between flexion and

extension forces across each finger

interphalangeal (IP) joint Kaplan5

recognized that any injury causing a

flexion or extension deformity in

one IP joint can lead to tendon

im-balance, creating an opposite

defor-mity in the adjacent IP joint (Fig 2)

At the DIP joint, the flexor

digi-torum profundus flexion force is

counterbalanced by the terminal

ex-tensor tendon At the level of the PIP

joint, the flexion forces of the flexor

digitorum profundus and

superficia-lis tendons are counterbalanced by

the extension forces of the conjoined

lateral bands and the central slip of

the extensor apparatus

With a mallet injury, the delicate

balance between flexion and

exten-sion forces is disrupted The

discon-tinuity of the terminal extensor

ten-don allows the extensor apparatus to

migrate proximally, thus increasing

extensor tone at the PIP joint

rela-tive to the DIP joint The resulting

imbalance can lead to an early or late

swan neck deformity

(hyperexten-sion of the PIP joint with

concomi-tant flexion of the DIP joint)

Classification

Acute mallet deformities have been arbitrarily defined as those occurring within 4 weeks of injury; chronic de-formities are those presenting later than 4 weeks from injury.8,9The clas-sification scheme developed by Doyle2 divides mallet injuries into four types (Table 1) Type I lesions in-volve closed trauma to the fingertip, with or without a small avulsion frac-ture at the dorsal base of the distal phalanx, resulting in loss of terminal extensor tendon continuity Type II injuries are open tendon injuries caused by laceration at or around the DIP joint Type III lesions are also open injuries; they occur from a deep soft-tissue abrasion with loss of skin and tendon substance Type IV lesions present as mallet fractures and are subclassified into three types Type IVA lesions are distal phalanx physeal injuries in children Type IVB lesions are distal phalanx fractures in adults involving 20% to 50% of the joint surface Type IVC injuries are caused

by hyperextension, resulting in a frac-ture fragment measuring >50% of the distal phalanx articular surface; they are associated with DIP joint volar subluxation This subclassification of mallet fractures corresponds to the categorization scheme proposed by Damron and Engber.10 Wehbé and

Schneider11developed their own clas-sification system for type IV injuries based on fracture size and presence or absence of DIP joint subluxation

Clinical Evaluation

Diagnosis of a mallet finger is relatively uncomplicated Patients present with pain, deformity, and/or difficulty using the affected finger.1

Posteroanterior, oblique, and lateral radiographs of the digit are recom-mended to assess for bone injury and joint alignment The examination begins with an inspection of the soft tissues as well as measurements of finger MCP and PIP joint motion In acute injuries, tenderness is elicited with palpation over the dorsal mar-gin of the DIP joint Although most patients develop an extensor lag at the DIP joint immediately after

inju-ry, the deformity may be delayed by

a few hours or even days Concur-rent hyperextension of the PIP joint (ie, swan neck posture) may be

not-ed with active finger extension

Management of Acute Mallet Finger Injuries

Several options are available for managing acute mallet finger

inju-Figure 2

Lateral view demonstrating the balance between flexion and extension forces at the

finger joints The single dots represent the axes of flexion-extension at each joint

The double dots represent the areas of action of the corresponding tendons at each

joint (Adapted with permission from Kaplan EB: Anatomy, injuries and treatment

of the extensor apparatus of the hand and digits Clin Orthop 1959;13:24-41.)

Doyle’s Classification of Mallet Finger Injuries2

I Closed injury, with or without small dorsal avulsion fracture

II Open injury (laceration) III Open injury (deep abrasion involving skin and tendon substance)

IV Mallet fracture

A Distal phalanx physeal injury (pediatric)

B Fracture fragment involving 20% to 50% of articular surface (adult)

C Fracture fragment >50% of articular surface (adult)

Table 1

ries, including reassurance,

observa-tion, splint immobilizaobserva-tion, and

sur-gery Although there are no clearly

established criteria for an acceptable

result, Geyman et al3defined a

satis-factory outcome as one in which the

DIP joint exhibits a residual

exten-sor lag ≤20°, the DIP flexion arc is

≥50°, and the patient reports

mini-mal or no pain Neglecting mini-mallet

in-jury often results in permanent

stiff-ness and deformity at the DIP joint

level Although many splint

config-urations and surgical techniques

have been described over the last

century, the optimal treatment of

each type of mallet finger injury

re-mains controversial

Nonsurgical Management

Nonsurgical management has

been the standard of care for type I

mallet injuries as well as for closed

mallet fractures involving less than

one third of the articular surface

with no associated DIP joint

sublux-ation However, differences of

opin-ion exist regarding both the style of

splint and the duration of

immobili-zation necessary to achieve an

ac-ceptable outcome

Immobilization of both the PIP and DIP joints was previously thought to be necessary to relax the extensor hood and intrinsic muscu-lature during terminal extensor tendon healing Katzman et al12 per-formed a cadaveric study to deter-mine whether PIP joint motion would cause a tendon gap at the im-mobilized DIP joint They demon-strated that gapping of a disrupted terminal extensor tendon occurred

as a result of excursion of the distal tendon stump during DIP joint flex-ion, not because of retraction of the proximal portion of the tendon with simulated PIP joint extension They concluded that only the DIP joint need be immobilized in extension to allow healing of the mallet injury

Most authors currently advocate immobilization of the DIP joint alone.2,11,13In the presence of a swan neck deformity, however, Wehbé and Schneider11and Evans and Weight-man14have suggested temporary in-clusion of the PIP joint in flexion

Combined PIP and DIP joint splint-ing has not been conclusively proved

to restore tendon balance in a swan neck deformity

Splinting

Numerous splints have been de-vised for managing mallet finger injuries.1-3 Common examples in-clude the stack splint, the perforated thermoplastic splint, and the alumi-num foam splint (Fig 3) Wilson and Khoo15 have reported their experi-ence with a novel splint design, which they termed the Mexican hat splint This splint incorporates a

“buckle” over the DIP joint to alle-viate undue pressure on the healing terminal extensor tendon A steril-ized aluminum splint secured with sterile tape strips has been proposed

to treat mallet injuries in operating room personnel.16

Despite the many splints avail-able, the principles of treatment re-main constant The involved digit is immobilized in full extension or slight hyperextension across the DIP joint Excessive extension should be avoided because dorsal skin vascular compromise can occur when the joint is immobilized in more than 50% of the normal range for passive DIP joint hyperextension.15Patients are instructed on how to change the splint for periodic cleaning and ex-amination of the skin without al-lowing the DIP joint to flex Contin-uous immobilization is maintained for 6 to 8 weeks, followed by an ad-ditional 2-week period of nighttime splint use A new full-length course

of immobilization is recommended when the DIP joint is inadvertently flexed during treatment Frequent physician assessment and patient compliance are fundamental for suc-cessful nonsurgical treatment Two recent studies have provided information on the medium-term re-sults of splint treatment of mallet in-juries.17,18Okafor et al17used a stack splint to treat 31 patients with either

a soft-tissue mallet injury or a mal-let fracture At 5-year follow-up, they noted a 90% patient satisfaction rate, with an average DIP joint extension deficit of only 8.3° They concluded that a small residual extensor lag and radiographic evidence of DIP joint

os-Figure 3

Three different mallet finger splints A, Stack splint (Stax Finger Splint, Sammons

Preston Rolyan, Bolingbrook, IL) B, Perforated thermoplastic splint (Aquaplast

Splinting Material, Sammons Preston Rolyan) C, Aluminum foam splint.

teoarthritis did not preclude a

suc-cessful treatment result Foucher et

al18advocated the use of a dorsal DIP

joint extension splint made of

perfo-rated thermoplastic material They

assessed 78 patients at a mean of 5

years postinjury and noted a mean

ex-tensor lag of 5° and a mean active DIP

joint flexion of 61° The authors

re-ported no skin complications,

contin-ued splint treatment, and reported no

need for surgery in their study group

Casting

In 1937, Smillie described casting

of both IP joints to manage acute

mal-let finger injuries.2The plaster cast

was applied with the PIP joint in 60°

of flexion and the DIP joint in slight

hyperextension Inclusion of the PIP

joint in flexion subsequently has been

advocated as a means of preventing a

tubular cast from inadvertently

fall-ing off the ffall-inger.19 Although this

technique is infrequently used,

cast-ing may be beneficial in children and

in individuals who are deemed

non-compliant with splint treatment

Surgical Management

Type I Injury

Although splinting is the treat-ment of choice for most type I mal-let finger injuries, surgery may be ad-vantageous for individuals who are unable to comply with a splinting regimen or for patients who would have difficulty performing their jobs with an external splint (eg, surgeons, dentists, musicians).1,20To immobi-lize the DIP joint in extension, a transarticular Kirschner wire (K-wire) is driven longitudinally or ob-liquely across the DIP joint, with the tip buried in the middle phalanx

The distal end of the wire is either capped or cut beneath the skin sur-face The K-wire is removed after 6

to 8 weeks, followed by 2 weeks of nighttime extension splinting

Open Injuries (Types II and III)

There are few published reports regarding the management of acute open mallet injuries Nakamura and Nanjyo20 described three patients who sustained lacerations over the

DIP joint leading to permanent ex-tensor lag measuring between 45° and 60° They hypothesized that the large DIP joint extension deficits were caused by disruption of both the terminal extensor tendon and contiguous oblique retinacular liga-ments Allowing the extensor mech-anism to heal by bridging the scar with splinting was thought to pre-dispose the digit to a DIP joint exten-sor lag and secondary swan neck de-formity Open surgical repair was recommended, using a wire secured around the DIP joint and a transar-ticular pin Doyle2suggested a com-bination of surgical repair and splint-ing for acute tendon lacerations overlying the DIP joint His tech-nique involves a running suture to reapproximate both skin and tendon, followed by application of an exten-sion splint The suture is removed after 10 to 12 days, with splinting continued for 6 weeks

Type III mallet deformities, which involve loss of skin, subcuta-neous tissues, and tendon substance, are caused by deep abrasions, crush injuries, and degloving accidents These lesions are often difficult to treat because of exposure of both bone and articular cartilage Staged reconstructive surgery may be con-sidered with the goal of providing early skin coverage, followed by res-toration of extensor tendon function with insertion of a free tendon graft.2In severe cases, arthrodesis of the DIP joint with bone shortening

or fingertip amputation may be more appropriate

Mallet Fracture (Type IV)

Management strategies for the different subtypes of mallet fractures remain controversial Treatment al-ternatives include observation with reassurance, extension splinting, closed and open reduction with in-ternal fixation, and DIP joint arthro-desis.2,11,21A true lateral radiograph

of the injured digit is valuable for de-termining the size and displacement

of the fracture fragment as well as

Figure 4

Calculations for determining fracture fragment size, fragment displacement, and

distal interphalangeal joint subluxation A and B = the length of the involved bone

segments at the articular surface of the distal phalanx, C = the amount of fracture

fragment displacement, D = the distance between the midaxial lines of the middle

and distal phalanges (Adapted with permission from Wehbé MA, Schneider LH:

Mallet fractures J Bone Joint Surg Am 1984;66:658-669.)

the presence or absence of volar

sub-luxation of the distal phalanx (Fig 4)

Most authorities agree that closed

mallet fracture injuries involving

less than one third of the articular

surface and without DIP joint

sub-luxation can be reliably treated with

extension splinting alone

Wehbé and Schneider11 and

Schneider19 advocated nonsurgical

management of nearly all mallet

frac-tures, regardless of the size or

dis-placement of the fracture fragment or

the presence of volar subluxation of

the distal phalanx They

retrospec-tively reviewed 21 mallet finger

frac-tures managed with either splinting

alone or internal fixation of the

frac-ture fragment using pins and a

pull-out wire.11 Surgical treatment was

technically demanding, with a higher

complication rate than nonsurgical

management The only consistent

complication in the nonsurgical

group involved a dorsal prominence

overlying the DIP joint; this same

de-formity was seen in the surgically

treated patients The authors also

noted remarkable remodeling

poten-tial in the distal phalanx articular

surface (Fig 5) Additionally, the

ra-diographic appearance of the DIP

joint did not correlate with pain or

finger function at final assessment

Many surgeons advocate surgical

intervention for mallet fractures

in-volving more than one third of the

articular surface or for fractures with

associated DIP joint subluxation

Various techniques have been

de-scribed, including transarticular pin-ning of the DIP joint with or without fracture fragment fixation, tension-band constructs,10,21,22compression pinning,23and extension block pin-ning24,25 (Fig 6) All of these tech-niques involve placement of at least one K-wire to immobilize the DIP joint in extension Proponents of open reduction think that associated complications can be minimized by using meticulous surgical tech-nique Closed reduction with percu-taneous pinning has been advocated

by surgeons who are concerned about complications with open management They cite problems re-lated to reducing the small articular fragment, the inability to accurately assess DIP joint congruency, and the potential for injury to the tenuous soft-tissue envelope.24,25

Management of Chronic Mallet Finger Injuries

Patients who present for treatment more than 4 weeks after injury typ-ically report pain, dissatisfaction with the appearance of the digit, and interference with use of the finger for normal work and recreational activ-ities As with acute mallet injuries, both nonsurgical and surgical treat-ment measures have been advocated

Ten patients with chronic (4 to 18 weeks old) mallet finger injuries without swan neck deformity were treated with continuous extension

splinting of the DIP joint for 10 weeks.8Extensor lag was corrected

to <10° in all but one case The only complication was a recurrent mallet posture in two patients after discon-tinuation of splint treatment, and both patients had an excellent result after reapplying the splint for 8 weeks Patel et al8 concluded that splinting should be considered as an alternative to surgery for a chronic mallet finger deformity Garberman

et al9 found no differences in out-come between patients splinted

ear-ly (<2 weeks after injury) and late (>4 weeks after injury) They recom-mended DIP joint extension splint-ing for closed mallet injuries re-gardless of chronicity, including fractures involving less than one

Figure 5

Lateral radiograph of a remodeled mallet fracture The arrows indicate the old

frac-ture line The distal interphalangeal joint remains congruent

Figure 6

Extension block pinning technique

A,With the distal phalanx extended, a Kirschner wire is inserted proximal to

the fractured fragment B, The fracture

is reduced manually by directing the exposed end of the Kirschner wire

distally C, The wire is drilled into the

head of the middle phalanx, and a second wire is passed retrograde across the distal interphalangeal joint (Adapted with permission from Tetik C, Gudemez E: Modification of the extension block Kirschner wire

technique for mallet fractures Clin

Orthop 2002;404:284-290.)

third of the joint surface

Brzezien-ski and Schneider1advocated

splint-ing for all chronic mallet deformities

resulting from either neglect or

pre-vious failed treatment

Proponents of surgery argue that

chronic mallet finger may develop

pathologic features that interfere

with treatment results.13 A static

contracture of the extensor

mecha-nism can develop over time, making

it difficult to achieve apposition of

the tendon ends with simple

exten-sion splinting Surgical procedures

for chronic mallet finger deformities

are intended to stabilize the DIP

joint and improve active DIP joint

extension.20 Examples include

ter-minal extensor tendon shortening,

tenodermodesis, oblique retinacular

ligament reconstruction, and

Fow-ler’s central slip tenotomy

Lind and Hansen26described the

abbreviato operation, in which the extensor tendon is transected near the DIP joint and repaired directly, without overlapping and without ex-cision of damaged tendon tissue

Scar contraction at the repair site is thought to correct the flexion defor-mity The authors recommended performing the procedure within 3 months of injury in patients with marked ligamentous laxity to avoid progression to a swan neck

deformi-ty However, the procedure is not recommended before 6 months to al-low potential spontaneous correc-tion of the extensor lag Their tech-nique includes using a transarticular pin to immobilize the DIP joint in extension for 6 weeks

Tenodermodesis, originally de-scribed by Iselin et al,27 has been used to manage chronic mallet fin-ger deformities in both adults and

children.28This procedure involves resection of an elliptical wedge of skin, tendon, and scar tissue with re-approximation of the skin and ten-don as a single unit with sutures (Fig 7) Similar to the abbreviato op-eration, a temporary K-wire is used

to maintain the DIP joint in full ex-tension during the healing process The spiral oblique retinacular lig-ament reconstruction procedure was devised to address the imbalance of flexion and extension forces contrib-uting to a chronic mallet deformity This procedure, which restores the dynamic tenodesis effect of the ob-lique retinacular ligaments in coor-dinating PIP and DIP joint exten-sion, was originally reported by Thompson et al29and was later mod-ified by Kleinman and Petersen.30A free tendon graft is harvested and se-cured distally to the dorsal base of the distal phalanx The graft is passed volarward in a spiral fashion around the radial aspect of the mid-dle phalanx and is secured

proximal-ly to the ulnar side of the flexor tendon sheath at the level of the proximal phalanx or directly to bone (Fig 8) The PIP and DIP joints are temporarily immobilized with K-wires before initiating finger mo-tion exercises

Fowler’s central slip tenotomy cor-rects for increased extensor tone at the PIP joint resulting from retraction

of the extensor apparatus (Fig 9) Houpt et al31recommended delaying the operation until at least 3 months after injury to allow restoration of ter-minal extensor tendon continuity by scar tissue To prevent boutonnière deformity, the triangular ligament bridging the two conjoined lateral bands must be preserved when cut-ting the extensor mechanism.32 Un-like the other corrective procedures, active finger motion is permitted im-mediately after surgery

Arthrodesis is the primary sal-vage procedure for patients with painful mallet finger injuries second-ary to arthritis, deformity, infection, and/or failed prior surgery

Arthro-Figure 7

Tenodermodesis procedure in which a 3- to 4-mm elliptical wedge of skin,

subcuta-neous tissue, and tendon/scar is resected A, The full-thickness defect is repaired

with nonabsorbable sutures B, Before securing the sutures, the distal

interpha-langeal joint is immobilized in extension with a Kirschner wire

desis of the DIP joint can be effec-tively performed with K-wires, ten-sion band wiring, or intramedullary screw fixation33 (Fig 10) The DIP joint is positioned between neutral and 10° of flexion Arthrodesis pro-vides reliable pain relief and early PIP joint finger motion

Complications

Stern and Kastrup34reported compli-cations with nonsurgical and surgi-cal management in 123 mallet finger injuries They noted a 45% compli-cation rate in the digits treated with extension splinting and a 53% com-plication rate in the digits treated surgically Most of the complica-tions from splinting were transient and resolved with adjustment of the splint or after completion of treat-ment Complications included skin maceration and ulceration, tape al-lergy, transverse nail plate grooves, and splint-related pain The only long-term splint complication was a transverse nail plate groove in one

Figure 9

Dorsal (A) and lateral (B) views of Fowler’s central slip tenotomy The central slip is

transected immediately proximal to its insertion on the base of the middle phalanx

The lateral bands and triangular ligament are preserved

Figure 8

Spiral oblique retinacular ligament reconstruction A, Lateral view The tendon graft

is secured to the dorsum of the distal phalanx with a pullout suture or wire The

graft is passed along the radial border of the middle phalanx, deep to the

neurovas-cular bundle and volar to the flexor tendon sheath B, Volar view The graft is then

sutured to the ulnar edge of the flexor tendon sheath at the level of the proximal

phalanx (Adapted with permission from Kleinman WB, Petersen DP: Oblique

retinacular ligament reconstruction for chronic mallet finger deformity J Hand Surg

[Am] 1984;9:399-404.)

Figure 10

Posteroanterior (A) and lateral (B)

radiographs of a distal interphalangeal joint arthrodesis Fixation was achieved with a headless differential-pitch compression screw (Courtesy of Acutrak Headless Compression Screw System, Acumed, Hillsboro, OR.)

patient present after 2 years In

con-trast to the transient nature of the

splint complications, 76% of the

complications associated with

surgi-cal treatment were long-term

Re-ported problems included infection,

nail plate deformity, joint

incongru-ity, hardware failure, DIP joint

prominence, and DIP joint

deformi-ty Five surgically treated patients

eventually underwent a second

oper-ation for pain There were four DIP

joint arthrodesis procedures and one

fingertip amputation

Summary

Mallet finger injuries are common

and involve disruption of the

termi-nal extensor mechanism overlying

the DIP joint Nonsurgical

manage-ment with immobilization of the

DIP joint in extension is the

treat-ment of choice in the vast majority

of cases Management strategies for

mallet fractures involving more than

one third of the articular surface

and/or fractures with volar

sublux-ation of the distal phalanx remain

controversial Some authors have

re-ported good functional results with

nonsurgical management; others

have proposed various surgical

pro-cedures to improve fracture and joint

alignment Although splint

treat-ment is simple and associated

com-plications typically are transient and

benign, patient education, with

care-ful attention to detail, is necessary

to ensure an optimal outcome

Sur-gical correction of a mallet

deformi-ty may be elected based on the

expe-rience of the treating surgeon with

failure of nonsurgical management

Patients should be informed of the

potential for a residual DIP extensor

lag and swan neck finger deformity

with all methods of treatment

References

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