Posttraumatic volar tendon subluxation out of the first extensor compartment: a case report.

Symptomatic volar subluxation of the abductor pollicis longus and the extensor pollicis brevis tendons developed in a 29-year-old man after a sprain that occurred with the wrist in flexion and ulnar deviation. The extensor retinaculum, which forms the extensor compartment, was partially avulsed from its insertion on the radius. Palmar abduction and extension of the thumb with the wrist flexed produced subluxation of the tendons over the volar side of the radius ridge where the retinaculum forming the first extensor compartment attached. Nonoperative treatment including steroid injection and splinting was ineffective. Surgery was performed to reconstruct a new tendon restraint with part of the extensor retinaculum.