"Gamekeeper's" Thumb

“Gamekeeper’s” Thumb

CR – Minimally displaced and rotated triangular bony fragment emanating from the ulnar aspect of the proximal phalanx of the thumb.

Injury of the ulnar collateral ligament (UCL) of thumb at the MCP joint may be referred to as “gamekeeper’s”, “skier’s” or “breakdancer’s” thumb. Integrity of the ulnar collateral ligament is required for the thumb to grab or sqeeze (such as when holding your keys or buttoning a shirt), and consequently injuries can be very disabling. UCL injury occurs after violent hyperabduction of the thumb. Rupture of the UCL may be total or partial and usually takes place at its distal point of insertion. It might be accompanied by bone avulsion. A spectrum of instability may exist, depending on whether there is additional injury to the adductor pollicis aponeurosis, joint capsule or volar plate. If the fragment becomes lodged between adductor pollicis aponeurosis and its its normal position it is termed a Stener lesion; this lesion must be treated surgically to avoid chonic instability.

Hinke DH, Erickson SJ, Chamoy L, et al. Ulnar collateral ligament of the thumb: MR findings in cadavers, volunteers, and patients with ligamentous injury (gamekeeper’s thumb). AJR (1994); 163(6): 1431-1434.

Clavero JA, Alomar X, Monill JM, et al. MR Imaging of Ligament and Tendon Injuries of the Fingers. RadioGraphics (2002); 22; 237-256.