Introduction
- A. Lee Osterman, MD
- Abdo Bachoura, MD
- Sidney M. Jacoby, MD
- Terri M. Skirven, OTR/L, CHT
- Jason A. Suda, MOTR/L
- Abdo Bachoura, MD
Epidemiology
Age/Sex
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Age: Predominantly in young, active individuals involved in contact sports
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Mallet finger
- •
Definition: a finger injury that involves damage to the terminal extensor tendon insertion on the dorsal aspect of the distal phalanx, resulting in inability to actively extend the distal interphalangeal joint ( Fig. 16-1 )
FIGURE 16-1
Small finger mallet injury characterized by loss of active extension at the DIP joint with resting posture of the DIP joint in flexion.
(Reprinted with permission from Hart RG, Kleinert HE, Lyons K: The Kleinert modified dorsal finger splint for mallet finger fracture. Am J Emerg Med 23:145–148, 2005.)
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Predominantly in young active males involved in contact sports
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Males 1.5 times more affected than females in the general population
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In a study by Simpson et al. 851 patients presented with acute sport injuries. 18 presented with Mallet injuries, and 17 of these were men.
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Incidence 10 to 19 year old males 1.2/10,000 per year
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Incidence 10 to 19 year old females 0.5/10,000 per year
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Incidence 20 to 29 year old males 1.5/10,000 per year
- •
Incidence 20 to 29 year old females 0.4/10,000 per year
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Incidence 30 to 39 year old males 1.3/10,000 per year
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Incidence 30 to 39 year old females 0.5/10,000 per year
- •
- •
Jersey finger
- •
Definition: a finger injury that involves damage to the flexor digitorum profundus tendon, resulting in inability to actively flex the distal interphalangeal joint ( Fig. 16-2 )
FIGURE 16-2
Jersey finger injury seen in the ring digit, causing inability to flex the DIP joint and make a full fist.
(Courtesy of Mr. Michael Hayton, MB.ChB, FRCS.)
- •
Sex: predominantly in males, although female involvement has also been reported
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Sport
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Mallet finger
- •
Any contact sport such as softball, baseball, football, basketball, or soccer in which the hand is subjected to force from a ball or another player
- •
In most instances, the player’s distal phalanx is subjected to some type of crush injury (often resulting in a distal phalanx fracture) or the distal interphalangeal joint (DIP) is forced into flexion (often resulting in a rupture of the terminal extensor tendon with or without a chip of bone).
- •
- •
Jersey Finger
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Mainly football and rugby
- •
Any contact sport in which the athlete’s hand is subjected to blunt forces from a ball or other player. It is seen in sports wherein an athlete’s finger is forced into extension while trying to maintain a flexed position (i.e., rock climbing or when an athlete grabs another player’s jersey who then quickly breaks away)
- •
- •
Injury is common in any full contact sports, but mallet and jersey fingers represent a small number of traumatic injuries that occur in these sports.
- •
Rugby is still growing in popularity in the United States. As such, research is still lacking in the area. However, in high school students “rugby appears to have a lower injury rate than ice hockey, higher injury rates than basketball and soccer, and similar injury rates to football and wrestling.”
Position
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Mallet finger
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Fielders in baseball and softball, receivers in football, goalkeeper in soccer
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Jersey finger
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Defensive players involved in tackling
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Because of the nature of rugby, all playing positions require tackling. As such, it does not appear that any playing position results in a higher incidence of jersey or mallet finger injuries. The authors do not know of any literature that reports the predominance of these injuries with any specific position in rugby.
Pathophysiology
Intrinsic Factors
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Mallet finger
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Extensor tendon insertion as the terminal tendon on the base of the dorsal aspect of the distal phalanx
- •
- •
Jersey finger
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The ring finger is the most frequently involved because it has the least independent motion, has a weaker flexor tendon insertion than the long finger, and absorbs most of the force during grip.
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Extrinsic Factors
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Mallet Finger
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The distal location of the finger tip
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Catching a ball flying at a high velocity
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Poor catching form or a lack of concentration during catching may contribute to this form of injury
- •
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Jersey Finger
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The player gets his or her finger caught in a jersey of a strong fabric worn by another player.
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- •
Quarrie et al. studied risk factors for injury in rugby players. They found the following factors to be associated with injury rate or time lost to injury: being in a higher grade, cigarette smoking, a history of prior injury, and a body mass index greater than 26.5. This study focused on general injuries of rugby players; it is speculated that similar factors would contribute to flexor or mallet finger in rugby players.
Traumatic Factors
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Mallet Finger
- •
Can often occur when any type of force pushes the extended DIP joint into flexion. As the player extends his/her fingers to catch an incoming ball, the ball strikes the fingertips, forcing sudden flexion of the DIP joint.
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Sudden flexion will lead to avulsion of the extensor tendon off the dorsal surface of the distal phalanx.
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Can also occur when an athlete hits the distal end of his finger against another player, ground, or any other solid object.
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Jersey Finger
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Forced hyperextension of the DIP joint while the finger is actively flexing.
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The flexor digitorum profundus (FDP) tendon is avulsed off the volar surface of the distal phalanx
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Often associated with an eccentric load on the flexed DIP joint. This is often seen when a player grabs another player’s jersey who quickly pulls away, hence the name “Jersey Finger.”
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Classic Pathological Findings
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Mallet finger
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Doyle classified mallet finger into four types:
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Type I: Closed trauma with loss of tendon continuity with or without avulsion fracture
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Type II: Laceration at distal interphalangeal joint with loss of tendon continuity
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Type III: Deep abrasion with loss of skin, subcutaneous tissue and tendon substance
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Type IVA: Transepiphyseal fracture in children
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Type IVB: Fracture fragment of the articular surface involving 20% to 50% of the distal phalanx
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Type IVC: Hyperextension injury with articular fracture >50% the distal phalanx joint surface
- •
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Avulsion of the extensor tendon off its insertion on the base of the dorsal distal phalanx (also known as a soft tissue mallet)
- •
An intraarticular bony fragment may or may not be avulsed at the insertion of the extensor mechanism (also known as a bony mallet).
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As a result, a patient with mallet finger will have no active extension of the DIP joint and will have a significant extensor lag (see Fig. 16-1 ).
- •
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Jersey finger
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Avulsed FDP with or without a bone fragment
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Retraction of the FDP to a various degree
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Ruptured vincula disrupts nutrition to the tendon
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Muscle contraction occurs within ten days, making it difficult, if not impossible to regain original tendon length
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Tendon sheath scarring occurs within 7 to 10 days of injury
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There are five types of jersey finger:
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Type I: The avulsed tendon retracts to the level of the palm. With this, the vinculum blood supply is often disrupted.
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Type II: The avulsed tendon retracts to the proximal interphalangeal (PIP) joint. The vinculum blood supply stays intact.
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Type III: The avulsed tendon has a large bony fragment attached and is at the level of the A4 pulley ( Fig. 16-3 ).
FIGURE 16-3
Type 3 Jersey finger: The avulsed tendon has a large bony fragment attached and is at the level of the A4 pulley.
(Reprinted with permission from Kang N, Pratt A, Burr N: Miniplate fixation for avulsion injuries of the flexor digitorum profundus insertion. J Hand Surg Br 28:363–368, 2003).
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Type IV: A combination of bone avulsion and a separate tendon avulsion. The FDP can then retract to flexor sheath or to the palm.
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Type V: A combination of bony avulsion and a comminuted distal phalangeal fracture
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A patient with jersey finger will have weakened grip strength and will show no active DIP motion with manual muscle testing of the FDP of the involved finger.
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Clinical Presentation
History
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Mallet finger
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Patient unable to straighten the DIP joint of the involved finger (see Fig. 16-1 )
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Pain over the DIP joint is usually present.
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May be painless
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Finger swelling
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Jersey finger
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The patient often feels a pop in the finger.
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Pain over the DIP joint may or may not be present.
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Finger bruising may or may not be present.
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Patients are unable to flex the DIP joint and cannot make a complete fist because the injured finger cannot flex to the palm.
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In both of the injuries, the patient often reports feeling a “pop” in the finger.
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Both injuries can result from blunt trauma to the hand. This can be the athlete’s hand hitting the ball or while tackling or grappling with another player.
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Most players will continue to play the game despite the injury reporting “I just thought I jammed my hand.”
Physical Examination
Abnormal Findings
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Mallet Finger
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Loss of active DIP joint extension
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Swelling, tenderness, and ecchymosis over the dorsal aspect of the DIP joint
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Resting posture of DIP joint in flexion
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Proximal interphalangeal PIP joint hyperextension can appear with attempts to extend the DIP joint, particularly in individuals with joint laxity
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May observe a subungual hematoma in the nail of the involved finger
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Jersey finger
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Inability to actively flex the DIP joint (see Fig. 16-2 )
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Swelling and ecchymosis over the DIP joint can be observed.
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Tenderness can be elicited over the DIP joint.
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Jersey Finger can sometimes involve hyperextension of the DIP joint owing to lack of balance between the flexor and extensor.
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Limited PIP flexion can also be seen if the FDP retracts to the PIP joint. If the FDP retracts even further to the palm the athlete may then report tenderness in the palm.
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Inability to make a fist
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Pertinent Normal Findings
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Mallet Finger
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Active flexion of the DIPJ is maintained.
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Usually a closed injury with no break in the skin
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Capillary refill should be normal.
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Sensation in the fingertip should be intact.
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Jersey Finger
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Active extension of the DIP joint is maintained.
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Usually a closed injury without a break in the skin
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Capillary refill should be normal, less than 2 seconds.
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Sensation in the tip of the finger should be intact.
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Imaging
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Mallet finger
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Standard posteroanterior, oblique, and lateral x-rays of the involved finger should be sufficient to determine whether bone avulsion has occurred.
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Jersey finger
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Standard posteroanterior, oblique, and lateral x-rays of the involved finger should be sufficient to determine whether bone avulsion has occurred.
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For chronic jersey finger injuries ultrasound or MRI can be useful because they can help determine the level of tendon retraction ( Fig. 16-4 ).
FIGURE 16-4
MRI and ultrasound of chronic jersey finger helping to determine the level of tendon retraction.
(Reprinted with permission from Masaki F, Isao T, Aya Y, Ryuuji I, Yohjiroh M: Spontaneous flexor tendon rupture of the flexor digitorum profundus secondary to an anatomic variant. J Hand Surg Am 32:1195–1199, 2007).
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Differential Diagnosis
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Mallet finger
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Transverse distal phalangeal fracture: Radiographic findings can determine the type and nature of the distal phalangeal fracture.
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Seymour’s fracture: Open fracture through the nail bed especially in children with active growth plates. Careful physical exam and radiographs can rule out this type of frequently missed injury ( Fig. 16-5 ).
FIGURE 16-5
Pediatric Seymour’s fracture.
(Reprinted with permission from Al-Qattan MM: Extra-articular transverse fractures of the base of the distal phalanx (Seymour’s fracture) in children and adults. J Hand Surg Br 26:201–6, 2001).
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PIP joint volar injury and/or laxity resulting in Swan neck deformity with hyperextension of the PIP joint and flexed posture of the DIP joint ( Fig. 16-6 )
FIGURE 16-6
PIP joint volar injury and/or laxity resulting in Swan neck deformity with hyperextension of the PIP joint and flexed posture of the DIP joint (see Fig. 16-5 ).
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Jersey Finger
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Transverse distal phalangeal fracture: Radiographic finding can determine the type and nature of the distal phalangeal fracture.
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Treatment
Nonoperative Management
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Mallet finger
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Volar or dorsal orthotic positioning of the DIP joint in full extension for 2 to 6 months, depending on the extent of injury and patient progress ( Fig. 16-7 ).
FIGURE 16-7
Mallet finger orthosis positioning the DIP joint in extension.
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Most mallet injuries can be treated with orthoses.
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Insufficient evidence to support superiority of a specific type of orthosis.
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Jersey finger
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Jersey finger cannot be corrected without surgery, but an athlete can still have a high level of functioning without active flexion of the DIP joint. However, the long-term consequences must be weighed before making this decision.
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Nonsurgical management after injury includes early mobilization emphasizing range of motion exercises.
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Guidelines for Nonoperative Treatment
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Mallet Finger
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Closed injury
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No bony avulsion
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Bony avulsion that is minimally displaced and is less than 30% of the articular surface of the distal phalanx
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Patient’s ability to understand and comply with the orthotic use protocol
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Jersey finger
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Nonsurgical treatment is reserved for chronic injuries or in those individuals who are either unwilling or unable to comply with a vigorous postoperative therapy protocol.
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Nonsurgical management requires the patient’s understanding of the permanent loss of active DIP joint flexion.
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Surgical Indications
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In general, jersey finger is treated surgically when diagnosed without delay.
Absolute
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Mallet finger
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Open injuries
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Closed fracture with more than 30% of the articular surface displaced ( Fig. 16-8 )
FIGURE 16-8
Mallet fracture: bony avulsion that is minimally displaced and is less than 30% of the articular surface of the distal phalanx.
(Reprinted with permission from Zhang X, Meng H, Shao X, Wen S, Zhu H, Mi X: Pull-out wire fixation for acute mallet finger fractures with k-wire stabilization of the distal interphalangeal joint. J Hand Surg Am 35:1864–1869, 2010.)
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Jersey finger
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Open Injuries
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Diagnosis is made early and surgery can be performed within 7 to 10 days of injury, although there are reports of successful repair in injuries outside this window of injuries.
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Types 1 to 5 injuries
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Relative
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Mallet finger
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Chronic injuries, more than 6 months old that have failed conservative treatment
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Demand for faster recovery and earlier return to function
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Cosmetic preferences
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Poor patient compliance
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Jersey finger
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Chronic injuries
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Aspects of History, Demographics, or Exam Findings that Affect Choice of Treatment
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Mallet finger
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Patient age
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Hand dominance
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Patient occupational demands
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Cosmetic preferences: Surgical treatment may lead to an improved cosmetic appearance.
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Recovery period: Surgical treatment often leads to a faster recovery and less daily impedance as a result of no splint wear.
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Jersey finger
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The time elapsed since injury
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Within 7 to 10 days of injury the injured tendon retracts and scars, rendering surgical treatment less effective.
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Size of bony fragment
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Extent of proximal retraction of the tendon
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Age
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Patient demand
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Aspects of Clinical Decision Making When Surgery is Indicated
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Mallet finger
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Degree of bony displacement
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Acuity or chronicity of the injury
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Patient age and growth plate status
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Jersey finger
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Type of jersey finger seen ( Pathophysiology section )
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Evidence
Mallet Finger
Jersey Finger
Rugby Injuries
Multiple-Choice Questions
Mallet Finger
- QUESTION 1.
What kind of fingertip injury clinically presents similar to a mallet finger and should be ruled out immediately because of its potential for causing complications?
- A.
Transverse fracture of the distal phalanx
- B.
Jersey finger
- C.
Seymour’s fracture
- D.
Subungual hematoma
- A.
- QUESTION 2.
Most mallet injuries can be treated with
- A.
open reduction and internal fixation.
- B.
splinting.
- C.
percutaneous pinning.
- D.
observation.
- A.
- QUESTION 3.
A surgeon may perform surgery to treat a mallet injury if
- A.
the injury occurred 1 month prior to presentation.
- B.
the injury occurred 6 months prior to presentation.
- C.
the patient demands surgery because he/she has read that surgery results in better cosmetic outcomes.
- D.
the injury involves 35% of the articular surface of the distal phalanx and was displaced.
- A.
- QUESTION 4.
Mallet finger injures are characterized by
- A.
loss of passive DIP joint extension.
- B.
resting posture of PIP joint hyperextension.
- C.
loss of active DIP joint extension.
- D.
inability to flex the DIP joint.
- A.
- QUESTION 5.
Mallet finger injuries are most often treated with
- A.
3 weeks of nighttime splinting.
- B.
DIP joint ROM exercises and taping.
- C.
6 to 8 weeks of uninterrupted DIP joint extension splinting.
- D.
splinting of the DIP and PIP joints for 1 month during the day.
- A.
Jersey Finger
- QUESTION 6.
Acute flexor digitorum profundus avulsion injuries should be treated surgically as early as possible because
- A.
tendon sheath scarring tends to occur within 7 to 10 days of injury.
- B.
tendon retraction and myostatic contraction can permanently shorten the tendon.
- C.
rupture of the vincula disrupts the transport of nutrition to the tendon.
- D.
All of the above
- A.
- QUESTION 7.
The Ring finger is the most frequently involved digit in jersey finger because
- A.
the ring finger has the least independent motion.
- B.
the ring finger has a weaker FDP insertion compared to the long finger.
- C.
the ring finger absorbs most of the force during grip.
- D.
All the above
- A.
- QUESTION 8.
What factor is the least important when planning a surgery for jersey finger?
- A.
Hand dominance
- B.
The duration since injury
- C.
The level of tendon retraction
- D.
The size of the bony fragment
- A.
Answer Key
- QUESTION 1.
Correct answer: C (see Differential Diagnosis )
- QUESTION 2.
Correct answer: B (see Treatment )
- QUESTION 3.
Correct answer: D (see Surgical Indications )
- QUESTION 4.
Correct answer: C (see Classic Pathological Findings )
- QUESTION 5.
Correct answer: C (see Treatment .)
- QUESTION 6.
Correct answer: D (see Aspects of History, Demographics, or Exam Findings that Affect Choice of Treatment )
- QUESTION 7.
Correct answer: D (see Pathophysiology: Intrinsic Factors )
- QUESTION 8.
Correct answer: A (see Aspects of History, Demographics, or Exam Findings that Affect Choice of Treatment )
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