Extensor tendon injury of the distal interphalangeal joint (mallet finger)
- Rebecca Bassett, MD
Rebecca Bassett, MD
- Adjunct Clinical Assistant Professor
- University of North Carolina School of Medicine
A mallet finger injury is the most common closed tendon injury of the finger. The injury occurs most often in the workplace or during contact or ball-handling sports. It is most common in young to middle-aged males, which may reflect their higher rates of participation in such sports .
The diagnosis and management of mallet finger injuries will be reviewed here. Other finger injuries are discussed elsewhere. (See "Distal phalanx fractures" and "Flexor tendon injury of the distal interphalangeal joint (jersey finger)".)
Traumatic disruption of the terminal slip of the extensor tendon at the distal interphalangeal (DIP) joint is commonly referred to as a mallet finger (or less often as a baseball or drop finger) (figure 1). The terminal slip is responsible for extension of the DIP joint. A zone of relative avascularity just proximal to the extensor tendon insertion predisposes the tendon to injury at this site. A more detailed discussion of finger anatomy is found separately. (See "Finger and thumb anatomy".)
MECHANISM OF INJURY
Mallet finger occurs most commonly during collision sports, such as American football and rugby, or ball-handling sports, such as basketball and baseball. The injury is usually caused by a direct blow to the tip of the finger, such as when a ball strikes the fingertip or the fingertip strikes a rigid surface (figure 2). The axial load from the blow causes sudden, forceful flexion of the distal phalanx. This flexion damages the extensor tendon where it attaches to the proximal portion of the distal phalanx. Less frequently, a mallet finger may occur as part of finger injuries involving dorsal lacerations or crushing mechanisms.
With mallet finger injuries, the tendon may be partially torn, completely ruptured, or associated with an avulsion fracture of the distal phalanx. Unopposed flexion leads to a fixed flexion deformity (called extensor lag) at the DIP joint if the injury remains untreated (picture 1).
- Bendre AA, Hartigan BJ, Kalainov DM. Mallet finger. J Am Acad Orthop Surg 2005; 13:336.
- McCue FC 3rd, Meister K. Common sports hand injuries. An overview of aetiology, management and prevention. Sports Med 1993; 15:281.
- Lee SJ, Montgomery K. Athletic hand injuries. Orthop Clin North Am 2002; 33:547.
- Doyle JR. Extensor tendon-acure injuires. In: Operative Hand Surgery, 3rd ed, Green DP. (Ed), Churchill-Livingstone, New York 1993. p.1925.
- Tuttle HG, Olvey SP, Stern PJ. Tendon avulsion injuries of the distal phalanx. Clin Orthop Relat Res 2006; 445:157.
- Handoll HH, Vaghela MV. Interventions for treating mallet finger injuries. Cochrane Database Syst Rev 2004; :CD004574.
- Geyman JP, Fink K, Sullivan SD. Conservative versus surgical treatment of mallet finger: a pooled quantitative literature evaluation. J Am Board Fam Pract 1998; 11:382.
- Weber P, Segmüller H. [Non-surgical treatment of mallet finger fractures involving more than one third of the joint surface: 10 cases]. Handchir Mikrochir Plast Chir 2008; 40:145.
- Wehbé MA, Schneider LH. Mallet fractures. J Bone Joint Surg Am 1984; 66:658.
- Facca S, Nonnenmacher J, Liverneaux P. [Treatment of mallet finger with dorsal nail glued splint: retrospective analysis of 270 cases]. Rev Chir Orthop Reparatrice Appar Mot 2007; 93:682.
- Kalainov DM, Hoepfner PE, Hartigan BJ, et al. Nonsurgical treatment of closed mallet finger fractures. J Hand Surg Am 2005; 30:580.
- Kiefhaber TR. Closed tendon injuries in the hand. Operative Techniques in Sports Medicine. 1996; 4:227. http://www.optechsportsmed.com/article/S1060-1872(96)80023-2/abstract (Accessed on June 13, 2011).
- Katzman BM, Klein DM, Mesa J, et al. Immobilization of the mallet finger. Effects on the extensor tendon. J Hand Surg Br 1999; 24:80.
- Hart RG, Kleinert HE, Lyons K. The Kleinert modified dorsal finger splint for mallet finger fracture. Am J Emerg Med 2005; 23:145.
- Warren RA, Norris SH, Ferguson DG. Mallet finger: a trial of two splints. J Hand Surg Br 1988; 13:151.
- O'Brien LJ, Bailey MJ. Single blind, prospective, randomized controlled trial comparing dorsal aluminum and custom thermoplastic splints to stack splint for acute mallet finger. Arch Phys Med Rehabil 2011; 92:191.
- Maitra A, Dorani B. The conservative treatment of mallet finger with a simple splint: a case report. Arch Emerg Med 1993; 10:244.
- Pike J, Mulpuri K, Metzger M, et al. Blinded, prospective, randomized clinical trial comparing volar, dorsal, and custom thermoplastic splinting in treatment of acute mallet finger. J Hand Surg Am 2010; 35:580.
- Patel MR, Desai SS, Bassini-Lipson L. Conservative management of chronic mallet finger. J Hand Surg Am 1986; 11:570.
- Garberman SF, Diao E, Peimer CA. Mallet finger: results of early versus delayed closed treatment. J Hand Surg Am 1994; 19:850.
- Okafor B, Mbubaegbu C, Munshi I, Williams DJ. Mallet deformity of the finger. Five-year follow-up of conservative treatment. J Bone Joint Surg Br 1997; 79:544.
- Stern PJ, Kastrup JJ. Complications and prognosis of treatment of mallet finger. J Hand Surg Am 1988; 13:329.
- MECHANISM OF INJURY
- SYMPTOMS AND EXAMINATION FINDINGS
- RADIOGRAPHIC FINDINGS
- INDICATIONS FOR REFERRAL
- COMPLEX MALLET FINGER: SPLINTING OR SURGERY
- Acute mallet finger
- Chronic mallet finger
- RETURN TO WORK OR SPORT
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS