section name header

Pathophys and Cause ⬇

J Am Acad Orthop Surg 2001;9:389

Cause:Forced valgus loading of the metacarpo-phalangeal joint of the thumb

Pathophys:Sprain/rupture of ulnar collateral ligament or bony avulsion at insertion onto proximal phalanx

Epidemiology ⬆ ⬇

Fall on pole while skiing, classically gamekeepers twisting head off birds

Signs and Symptoms ⬆ ⬇

Sx:Immediate pain following fall; weakened grasp

Si:Swelling and redness at MCP. May be able to palpate avulsed tendon early in course before swelling. Pain and opening with valgus loading of MCP joint in 80° flexion

Course ⬆ ⬇

Grade I-II (partial tears): immobilize in thumb spica splint for 6 weeks, longer if pain and laxity persist. Grade III (complete tear, no endpoint to valgus stressing): surgical repair (see below)

Complications ⬆ ⬇

Stener’s lesion, related to complete UCL tear in which ligament end becomes trapped beneath palmar aponeurosis and does not heal.

Lab and Xray ⬆ ⬇

Xray:PA, lateral and oblique views of the finger. Valgus stress views only if fracture r/o. Stress angulation difference greater than 15° pos for UCL sprain

Treatment ⬆

Rx:Immobilization 6 wk—modified thumb spica cast vs splint. Surgery for grade III