Surgical treatment for recurrent dislocation of the extensor carpi ulnaris tendon.

Twelve patients with recurrent dislocation of the extensor carpi ulnaris tendon were treated with repair or reconstruction of its tendon sheath, and each had a satisfactory result. We found three types of disruption of the fibro-osseous sheath. Type A: the fibro-osseous sheath ruptured ulnarly and the torn sheath lay superficial to the tendon (n=5). These were treated by reconstruction of the sheath using a piece of the extensor retinaculum. Type B: the fibro-osseous sheath ruptured radially and the torn sheath lay in the ulnar groove beneath the tendon (n=3). These were treated by direct suture of the sheath over the tendon. Type C: detachment of the periosteum from the ulnar side of the ulna in continuity with the fibro-osseous sheath formed a false pouch into which the tendon easily dislocated (n=4). These were treated by reattachment of the periosteum.