Extensor Carpi Ulnaris Instability in Athletes - Diagnosis and Treatment

This article specifically focuses on extensor carpi ulnaris (ECU) tendon instability in athletes. ECU instability occurs when insufficiency of the fibro-osseous subsheath allows the ECU tendon to subluxate out of the distal ulnar groove, which may result in painful snapping of the tendon at the ulnar side of the wrist. Etiologies commonly include acute traumatic rupture of the subsheath or chronic degeneration of the subsheath. Injuries are often seen in stick, racquet, and club athletes (ie, hockey, baseball, golf, and tennis). A careful patient history and a physical examination are the keys to diagnosis, but advanced imaging can play a role, especially in the assessment of concomitant ulnocarpal compartment pathologies as causes of ulnar-sided wrist pain. Acute and chronic subsheath injuries comprise a spectrum of presentations including pain and apprehension with provocation of ECU instability, frank instability and painful ECU snapping, and a chronically incompetent subsheath with ECU tendinopathic changes and extensor tenosynovitis. Initial conservative treatment consists of forearm immobilization in pronation with the wrist immobilized in a position of extension and radial deviation. For persistent painful snapping of the ECU, in-season management may include the use of cortisone injection to attempt to achieve painless snapping until repair or reconstruction can be performed in the off-season. Surgical treatment is indicated in refractory cases and may consist of repair of the torn edge of the ECU subsheath or more frequently reconstruction of the extensor retinaculum to create a stabilizing sling for the tendon.