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Quick Splint for Acute Boutonniére Injuries

Mark S. Williams, DO; Jeff Fair, EdD, ATC; John Wilckens, MD

William O. Roberts, MD
Department Editor


Injuries to the proximal interphalangeal (PIP) joint are common in athletes, especially in contact and ball sports (1). Most PIP injuries involve disruption of the volar plate or dorsal dislocation. Less common is the "boutonniére" injury, which, if left undiagnosed and untreated, results in a boutonniére deformity. This deformity is difficult to manage and often requires prolonged immobilization and/or surgery to regain function (2).

The extrinsic extensor tendon has multiple interconnecting slips or bands at the level of the PIP joint, with the central slip attaching at the dorsal surface of the proximal middle phalanx (figure 1A). The two lateral bands continue distally and reunite at the level of the distal interphalangeal (DIP) joint. "Boutonniére" is French for buttonhole and refers to how the proximal aspect of the middle phalanx can project through the "buttonhole" created by the disrupted central slip and intact lateral bands (figure 1B).

Mechanism and Findings

The central slip can become injured by laceration, volar PIP joint dislocation or subluxation, forced flexion of an extended PIP joint, or by direct crush (2). A dorsal central slip injury may be difficult to diagnose. An obvious volar dislocation, dorsal laceration at the level of the PIP joint, or an avulsed fragment noted on x-ray alerts the practitioner to a central slip injury. Often, however, there is no easily identified abnormality shortly after injury.

The injured athlete typically develops PIP joint swelling and generalized tenderness, mostly over the dorsal surface of the PIP joint. Acutely, there may be a minimal PIP flexion deformity of 15° to 30° (1). The athlete usually can still achieve active PIP joint extension because the lateral bands have not yet displaced. Any injury to the PIP joint that has dorsally localized tenderness to palpation should be suspect for a central slip injury.

Early recognition and treatment of a central slip injury helps prevent formation of a boutonniére deformity. The injury to the central slip disrupts the delicate balance of the PIP joint, and the lateral bands gradually migrate toward the volar surface. Once the bands migrate below the center of rotation of the PIP joint, they cause PIP joint flexion instead of extension. In an attempt to extend the PIP joint, the subluxed lateral bands also cause a secondary hyperextension of the DIP joint. This hyperextension at the DIP joint is often more symptomatic than the abnormal flexion of the PIP joint. The deformity gradually develops over 10 to 21 days. A fixed deformity becomes a treatment challenge.

Making the Splint

The keystone to treatment is the immediate recognition of a closed central slip injury and early continuous splinting (3). Splinting should involve static and dynamic methods of rehabilitation to augment healing (4). The PIP joint is immobilized in full extension to approximate the central slip ends. The DIP joint is left free to allow and encourage DIP flexion, which enhances the tightening of the lateral bands and helps prevent volar migration. An ideal splint is easy to apply, with minimum restraints on the athlete's hand.

We have recently developed a quick, effective splint for central slip injuries. The quick splint is fabricated from 1/16-in. perforated Aquaplast-T Splinting Material (Smith & Nephew, Inc, Germantown, Wisconsin). The Aquaplast-T, a thermoplastic material, is cut into a "T" (figure 2). The top of the "T" will be on the palmar surface of the injured finger, and the bottom of the "T" will be wrapped around the extended PIP joint. The top of the "T" is reinforced with a slightly smaller piece of Aquaplast-T (see figure 2) to form the volar side of the splint.

Both pieces are heated in hot water until they become clear. The smaller piece and top of the "T" are then placed on the palmar aspect of the finger. The bottom of the "T" is wrapped around the PIP joint while it is still warm and will also reinforce the bottom of the splint under the PIP joint. The palmar side of the splint is then trimmed with scissors to ensure full range of motion at the DIP and metacarpophalangeal (MCP) joints (figure 3).

The quick splint can be precut to be readily available and quickly applied in the acute setting. Patients report the splint to be comfortable and very tolerable. The splint may be taken off and put back on, much like a ring, for bathing (figure 4). The splint may be reheated and reformed as swelling resolves, allowing for a secure, snug fit.

Among our experiences, through last year's football season, a defensive lineman and a punt returner were able to play unaffected while wearing the quick splint. Both continued splinting for 6 weeks continuously and followed with 2 weeks of splinting at night. Both players had full recovery of PIP extension without deformity.

Preventing Deformity

The quick splint represents an effective, easy, inexpensive, and well-tolerated treatment for central slip injuries.


  1. McCue FC III, Cabrera JM: Common athletic digital joint injuries of the hand, in Strickland JW, Retting AC (eds): Hand Injuries in Athletes. Philadelphia, WB Saunders Co, 1992, pp 49-94
  2. Hester PW, Blazar PE: Complications of hand and wrist surgery in the athlete. Clin Sports Med 1999;18(4):811-829
  3. Mastey RD, Weiss AC, Akelman E: Primary care of hand and wrist athletic injuries. Clin Sports Med 1997;16(4):705-724
  4. Alexy C, De Carlo M: Rehabilitation and use of protective devices in hand and wrist injuries. Clin Sports Med 1998;17(3):635-655

Dr Williams is the director of primary care sports medicine at Martin Army Community Hospital in Fort Benning, Georgia. Dr Fair is the director of athletic training services and Dr Wilckens is an orthopedic surgeon and the head team physician at the US Naval Academy in Annapolis, Maryland.