Mallet finger is characterized by complete or partial disruption of the extensor tendon’s attachment at the dorsal base of the distal phalanx with resultant flexed deformity of distal interphalangeal (DIP) joint. This is the most common closed tendon injury.
Mechanism of Injury: Forced flexion of the extended DIP joint, most commonly associated with catching a ball.
Clinical Presentation: Pain at dorsum of the DIP along with inability to actively extend the DIP joint. Partial tears may present with weak active extension (“extensor lag”).
Indications for Orthopedic Referral: Volar subluxation of the DIP joint, inability to fully extend DIP passively, and avulsion fracture involving greater than 30% of the articular surface.
Treatment: X-ray is used to evaluate for avulsion fracture of the distal phalanx, splint DIP joint in slight hyperextension continuously for 6 to 8 wk, then night splint only for 2 to 3 wk.
Follow-up and Return to Play: Consider repeat x-ray at 6 wk if avulsion fracture is present; may return to sport during the splinting phase.
Jersey finger is characterized by traumatic avulsion of the flexor digitorum profundus from the distal phalanx. The ring finger is most commonly affected.
Mechanism of Injury: The injury classically occurs when an athlete grabs an opposing player’s jersey with flexed fingers, causing forced passive extension of the DIP.
Clinical Presentation: Patients present with pain and inability to flex the DIP joint while stabilizing the proximal interphalangeal joint (PIP).
Indications for Orthopedic Referral: Emergent referral for all patients, splint finger with DIP and PIP in slight flexion while awaiting referral.
Treatment: Surgical reattachment of flexor tendon within 7 to 10 d if the tendon has retracted into the palm. If the tendon has only retracted to the PIP or if a bony avulsion has maintained ruptured tendon at the A4 pulley, reattachment can be delayed up to 3 wk.
Follow-up and Return to Play: Extensive postoperative hand therapy is required. Most require 12 wk of healing and protection from disruptive forces prior to return to play.
Boutonniere deformity is characterized by rupture of the central slip of the extensor tendon at the dorsal aspect of the middle phalanx.
Mechanism of Injury: Forced passive PIP flexion against active extension disrupting the central slip of the extensor tendon.
Clinical Presentation: Patients present with pain at the dorsal PIP and inability to actively extend the PIP joint against resistance. If not treated correctly, approximately 4 to 6 wk after the injury, the lateral bands of the extensor mechanism pull the PIP into flexion, which results in hyperextension at the DIP.
Indications for Orthopedic Referral: Patients with central slip extensor tendon injuries that are associated with a displaced dorsal avulsion fracture, which limits passive range of motion (ROM).
Treatment: PIP should be splinted in continuous full extension for 6 wk. The DIP and metacarpal phalangeal joints (MCP) should be left free for adequate ROM, as this helps bring the lateral bands closer to midline and speeds healing.
Follow-up and Return to Play: Return to sport may occur during splinting period, and a protective splint should be worn for an additional 4 wk after the initial 6-wk splinting period is completed.
Gamekeeper’s Thumb (“Skier’s Thumb”)
The gamekeeper’s thumb is characterized by a hyperabduction injury to the ulnar collateral ligament (UCL) of the MCP joint of the thumb.
Mechanism of Injury: Excessive abduction stress to the thumb MCP joint, combined with hyperextension.
Clinical Presentation: Patients present with pain at the ulnar aspect of the MCP; pinch strength is usually decreased.
Indications for Orthopedic Referral: Fractures at the base of the first phalanx displaced more than 2 mm or if there is ≥20% articular surface involvement. Complete tears as suggested by >35° opening on valgus testing or if there is concern for a stener lesion (adductor tendon or aponeurosis becomes interposed between the torn ligament and its insertion on the phalanx, preventing healing). Stener lesions require surgical repair because the UCL tendon is no longer in contact with its insertion site and cannot spontaneously heal, leading to instability of the thumb.
Treatment: Thumb keeper splint or thumb spica splint for 4 to 6 wk followed by a 2-wk splinting period with ROM exercises.
Follow-up and Return to Play: Typically return to play as tolerated with cast if sport allows.
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. 3rd ed. Atlanta (GA): Saunders Inc.; 2009. 1319–450 p.
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. 1st ed. Atlanta (GA): Saunders Inc.; 2010. 368–78 p.