UNUNITED ANCONEAL PROCESS OF THE CANINE ELBOW

Ununited anconeal process (UAP) is a developmental orthopedic disease affecting primarily large- and giant-breed dogs younger than 1 year. T he German shepherd breed is the most commonly affected. The anconeal p rocess is the proximal articular eminence of the trochlear notch of th e ulna. It arises from a separate ossification center that should radi ographically fuse with the olecranon by the time the dog is 20 weeks o ld. Clinical signs include weight-bearing lameness, joint effusion, jo int pain, crepitus, and decreased range of motion. The diagnosis is co nfirmed radiographically by a radiolucent line between the anconeal an d olecranon processes in an animal older than 20 weeks. The underlying pathogenesis of UAP appears to involve incongruous radial and ulnar g rowth. Treatment options include surgical excision, lag-screw attachme nt, and proximal ulnar osteotomy. Initial results seem to favor proxim al ulnar osteotomy, but more research is needed. Early surgical therap y is recommended, but osteoarthritis may persist and progress despite appropriate surgical intervention.