SONOGRAPHY OF THE INJURED ULNAR COLLATERAL LIGAMENT OF THE THUMB

We used high-resolution ultrasonography to image the ulnar collateral ligament in 39 patients who had sustained recent injuries of the metacarpophalangeal joint of the thumb. All the patients were subsequently operated on and the lesions of the ligament were recorded. In 36 patients the preoperative ultrasonographic diagnosis was correct. Five of these showed no rupture of the ligament. In the other 31, ultrasonography correctly distinguished between rupture in situ (15) and rupture with dislocation of the ligament (16). Misdiagnosis by ultrasonography in three cases was due to delay of the investigation (three weeks after injury) in one, to technical error in one and to misinterpretation of the image in one. J Bone Joint 5”v [Br] I995:77-B:77-83. Received 16 November 1993: Accepted atk’r revision 26 Ma 1994 Injuries of the ulnar collateral ligament of the thumb (UCL) have been reported many times since the first description by Bunnell in 1948. Campbell (1955) invented the term ‘gamekeeper’s thumb ’ to describe the laxity of this liga-ment which results from the repetitive trauma of killing rabbits. When skiing became a popular winter activity, injuries of the UCL increased dramatically and the term ‘skier’s thumb ’ is now in common use (Schultz and Fo