A rugby player injures his thumb when it is forcibly abducted during a tackle. There is tenderness over the ulnar side of the metacarpophalangeal joint, laxity to valgus stress, and a firm palpable lump just proximal to the adductor pollicis insertion. MRI confirms the ulnar collateral ligament is torn and retracted. The palpable lump represents:

• A The retracted ligament lying superficial to the adductor aponeurosis, requiring surgical repair ✓
• B An intact accessory collateral ligament, suitable for splinting alone
• C Avulsion of the abductor pollicis brevis tendon, treated conservatively
• D A displaced Bennett fracture fragment, requiring percutaneous pinning

Explanation

This is a Stener lesion complicating rupture of the ulnar collateral ligament of the thumb MCP joint (gamekeeper's or skier's thumb). When the ligament tears from its distal insertion, the adductor aponeurosis can interpose between the retracted stump and the insertion point, holding the ligament outside the aponeurosis as a palpable lump. Interposition prevents healing, so a Stener lesion mandates open repair. Conservative splinting is appropriate only for partial tears without retraction.

Reference: Miller's Review of Orthopaedics, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.