Traumatic extensor carpi ulnaris subsheath injury and subluxation
Presentation
Ulnar-sided wrist pain following sports injury playing tennis.
Patient Data
Intratendinous split lesion and slight palmar subluxation of the extensor carpi ulnaris (ECU) tendon. The tendon subsheath appears ill defined within an area of edema dorsal and radial to the ECU tendon.
Case Discussion
At the level of the wrist, the ECU is stabilized within a fibro-osseous tunnel formed by the distal ulna and a band of connective tissue known as the ECU subsheath. ECU subluxation or dislocation is usually traumatic, typically occurring during supination, ulnar deviation, and wrist flexion. Therapy usually consists of immobilizing the wrist in extension and radial deviation. Untreated subsheath lesions can lead to chronic ECU tendon instability, progressive tendinopathy and persistent tenosynovitis.