Cubitus varus associated with dislocation of both the medial portion of the triceps and the ulnar nerve

Five patients with cubitus varus deformities from malunited childhood fract ures had dislocation (snapping) of both the medial portion of the triceps a nd the ulnar nerve over the medial epicondyle. in addition to snapping, the se patients had medial elbow pain or ulnar nerve symptoms. Cubitus varus sh ifts the line of pull of the triceps more medial, which can cause anteromed ial displacement of the medial portion of the triceps during elbow flexion. The ulnar nerve is concomitantly pushed or pulled anteromedially by the tr iceps, and ulnar neuropathy may result from friction neuritis or from dynam ic compression by the triceps against the epicondyle. Recognition of both t he dislocating ulnar nerve and the snapping medial triceps is crucial in th e successful treatment of this pathologic finding. In symptomatic individua ls, we recommend either corrective valgus osteotomy of the distal humerus o r partial excision or lateral transposition of the snapping medial triceps, or a combination of both. Alternatively, medial epicondylectomy can also e liminate the snapping. Transposition of the ulnar nerve can be performed fo r ulnar nerve symptoms and/or ulnar nerve instability. Using this approach, correction of the snapping and/or ulnar nerve symptoms was achieved in all cases. (J Hand Surg 1999;24A:718-726. Copyright (C) 1999 by the American S ociety For Surgery of the Hand.).