[Modified collateral ligament reconstruction with the tendon of the abductor pollicis tendon in treatment of chronic radial instability of the basal thumb joint].

Injuries to the radial collateral ligament of the MP joint of the thumb occur much less frequently than injuries to the ulnar collateral ligament. Ligament injury is usually a result of direct trauma. The resultant instability to the thumb usually impairs hand function. In acute lesions to the radial collateral ligament, direct repair is often possible. In cases of chronic radial joint instability, secondary ligament reconstruction with a free tendon graft, most commonly the palmaris longus tendon, is usually recommended. We describe another technique using the tendon insertion of the abductor pollicis brevis muscle. The tendon inserting distally can be used as a stable ligament after dividing it at the border to the muscle and attaching it to the head of the metacarpal bone with a wire. The follow-up for six patients treated by this method showed good and painless stability and function of the thumb in a time span of one year.