Extensor Carpi Ulnaris Tendon Dislocation

Abstract

Objective: Extensor carpi ulnares (ECU) has a stabilizing role at distal radioulnar joint, and besides the extensor retinaculum coverage, it is held tight to the ulnar groove by the ECU subsheath. Graham (2012) described a reinforced insertion of the ECU subsheath at medial edge of ulnar sulcus that creates a labrum, a critical barrier for ECU subluxation. Forced supination, palmar flexion, and ulnar deviation can rupture or attenuate the ECU subsheath and the ECU tendon can dislocate, causing ulnar side wrist pain. We present our experience dealing with diagnostic (special test for ECU instability, dynamic ultrasound, and wrist MRI) and treatment details of ulnar side wrist pain related to ECU tendon dislocation. Material and Methods: From 2010 to 2015, we treated 9 patients with ulnar side wrist pain related to ECU dislocation. All patients had a failed conservative treatment (Immobilization + Physical Therapy) for at least 3 months. Diagnostic was confirmed by clinical examination, dynamic ultrasound, and magnetic resonance imaging (MRI) in supination/pronation. Patients were evaluated in terms of ECU instability tests, wrist range of motion, grip strength, analogic scale of pain, and return to sports activities. Results: There were 8 male and 1 female, average age of 34.5 year-old, and 7 of 9 dominant wrists were affected. Of all, 5 were tennis players, 2 basketball players, and 1 soccer goalkeeper. Minimum follow-up was 12 months. Seven of 9 patients had type A (Inoue & Tamura) injury, with subsheath rupture at ulnar side, and 2 out of 9 had type C (one had a tumor inside the subsheath that became redundant). All cases with ECU instability were submitted to labral reattachment to medial wall of ulnar sulcus with mini-anchor and retinacular subsheath sling reconstruction. All players had resolution of wrist pain, recovery wrist motion, and strength and went back to sport activity. Conclusion: The ECU dislocation must receive special attention because, probably, it is more common than we expected. Based on our small experience, we believe that surgical labrum reattachment is a good option to solve ECU recurrent dislocation.