"Gamekeeper's thumb". Injuries of the ulnar collateral ligament of the metacarpophalangeal joint.

The condition of chronic instability of the MP (metacarpophalangeal) joint of the thumb, may be the resultant of chronic strain of the ulnar collateral ligament of the MP joint. This condition was described in Scottish gamekeepers who used to kill hunted animals by a special manoeuvre subjecting the thumb to extension abduction force, and was termed "Gamekeeper's Thumb" (Campbell, 1955). Nowadays, such a chronic strain has been replaced by relatively frequent acute strains and tears subjected to the thumb during sport activities. The MP joint of the thumb, being a vulnerable one, is subjected to trauma on falling down with arms extended, during hand ball or volley-ball games, when the ball hits the distal end of thumb and subjects it to hyper-extension and hyper-abduction movement (Fig. 1), and in skiing. Injury to the base of the thumb is probably the most common ski injury of the upper extremity (Gutman et al 1974). The ski pole is held by the handle and the strap around the wrist prevents loosing the stick while standing or skiing. However, when the ski-pole is relatively fixed to the ground and the skier falls, the deceleration impact takes place over the MP joint of the thumb and subjects the latter to forced abduction (Browne et al, 1976). ILLUSTRATIVE CASE HISTORIES