Gamekeeper's thumb (skier’s thumb, ulnar collateral ligament tear) is due to forceful abduction of the thumb. It is a common sporting injury. MR imaging may be helpful to demonstrate the extent of tear.
The Stener lesion is where the ulnar collateral ligament is displaced superficial to the adductor pollicis aponeurosis. This may require operative repair. The term gamekeeper's thumb is thought to be due to the tear being acquired by repetitive breaking of rabbits necks.