Review Question - QID 1388

Fall from standing onto an extended and pronated wrist is a risk factor for injuries to the soft tissues of the wrist. The structures at risk include the triangular fibrocartilaginous complex (TFCC), the lunotriquetral ligament, ulnolunate ligament, hook of hamate, ulnar styloid, and the extensor carpi ulnaris (ECU) tendon sheath. Pain with resisted ulnar deviation and ulnar catching are all concerning for injury to the TFCC. MRI is useful for diagnosing TFCC tears ( Illustration A shows another example).

Papapetropoulos et al in their review article discuss the evaluation and arthroscopic treatment of TFCC injuries. Specifically they discuss that most tears in athletes are acute and amenable to repair by repair of the dorsal tear to the ECU tendon sheath.

Cohen in his review of injuries in athletes discusses scapholunate ligament, lunotriquetral ligament, and midcarpal injuries. Of note he divides scapholunate and lunotriquetral ligament injuries into dissociative lesions (abnormal motion within proximal carpal bones) vs. midcarpal lesions which are generally considered nondissociative (abnormal motion between proximal and distal carpal bones).

Rettig in his review of sports injuries of the extremities discusses the Palmer classification of TFCC tears. Specifically he notes that central tears are more associated with repetitive activities in patients with positive ulnar variance.

Incorrect Answers:
Answer 1: The patient is not tender in the region of the ECU tendon sheath.
Answer 3: The carpal tunnel view radiograph shows no hook of hamate fracture.
Answer 4 and 5: Wrist radiographs shows no scapholunate widening or perilunate dislocation. Physical exam in this case is more consistent with a TFCC injury.