A Novel Technique Using the Dorsal Capsule of the Distal Radioulnar Joint for Extensor Carpi Ulnaris Tendon Subsheath Reconstruction.

Background  Ulnar-sided wrist pain is a common problem encountered by hand surgeons. Symptomatic recurrent subluxation of the extensor carpi ulnaris (ECU) tendon has become increasingly recognized as one of the pathological conditions leading to ulnar-sided wrist pain. Surgical reconstruction of the subsheath is usually needed. ECU tendon subsheath reconstruction with the periosteal flap was first described by Schlesinger in 1907. Since then, various other techniques have been widely used. We describe a technique of ECU subsheath reconstruction using the dorsal capsule of the distal radioulnar joint (DRUJ). Description of Technique  Two hand surgeons performed the surgeries with the same steps taken each time. A detailed description of our surgical technique, with the dorsal capsule of the DRUJ used to reconstruct the ECU tendon subsheath, is illustrated. Patient and Methods  Patients who presented with symptomatic ECU instability despite conservative treatment or who have failed primary subsheath repair were offered this surgical option. Patients were followed up postoperatively for an average duration of 6.7 months in our outpatient clinics for assessment of wrist function. The surgical outcomes were reviewed and graded with the Modified Mayo Wrist Score (MMWS). Results  All but one of the seven patients had an overall improvement in their range of movement of the wrist, grip strength, and pain scores. Four patients had excellent outcomes on the MMWS, one of whom had an asymptomatic recurrence seen on dynamic ultrasound. Two patients required subsequent surgeries: one had an excellent outcome and the other had a poor outcome on the MMWS. Conclusion  We present our first seven cases of ECU subsheath reconstruction with the dorsal capsule of the DRUJ. Our results in the short term have been satisfactory. The technique does not disrupt the integrity of the extensor retinaculum, which is essential for optimal extensor tendon function, and can also be considered as an option to salvage failed procedures.