Two cases of traumatic subluxation of the carpometacarpal (CM) joint of the thumb are reported. The first case was caused by radial subluxation of the CM joint following forced extension and abduction of the right thumb. The patient was treated with taping, however, radial subluxation remained after 5 months. He then received intermetacarpal ligament reconstruction with a half slip of the extensor carpi radialis longus. At 15 months follow-up, the patient had neither pain nor instability and his CM joint was kept reduced on the radiograph.
The second case occurred after radial subluxation of the right thumb CM joint in a motor cycle accident. The patient had pain on pinching and showed radial subluxation even after receiving initial immobilization with a cast for 4 weeks. She was also treated by ligament reconstruction the same as the first case. At 9 months follow-up, she had no pain and her CM joint was kept reduced on the radiograph.
