Traumatic craniolateral shoulder luxation and fracture of the lesser tubercle of the humerus in a dog

A five-year old, spayed female, Bearded Collie was presented with a 24-hour history of non-weight-bearing lameness of the right thoracic limb after sustaining vehicular trauma. Radiographs revealed a craniolateral scapulohumeral luxation and a distally and medially displaced fracture of the lesser tubercle of the humerus. Open reduction and internal fixation of the fracture was achieved with lag screw fixation and an anti-rotational Kirschner wire. Surgical repair resulted in compression across the fracture line, anatomic reduction of the articular surface, and a stable scapulohumeral joint following reduction of the humeral head in the glenoid. Six weeks postoperatively, the patient exhibited no evidence of pain or lameness on the right thoracic limb and radiographs revealed complete healing of the fracture and normal articulation of the scapulohumeral joint. This is the first report of a lesser tubercle fracture associated with a craniolateral shoulder luxation. Surgical intervention resulted in the return of full shoulder joint function in this dog.