Arthroscopic surgical approaches and intraarticular anatomy of the equine shoulder joint.

Arthroscopic approaches to the scapulohumeral joint were developed in four clinically normal, live horses (5 limbs) to determine their usefulness for evaluation and potential surgical treatment of intraarticular lesions. The articular surface of the entire glenoid, cranial humeral head (medial and lateral) and caudolateral humeral head, as well as the synovial membrane, could be closely examined from an arthroscopic portal cranial to the infraspinatus tendon. The caudomedial humeral head could be examined partially. Cranial and caudal instrument portals allowed good surgical access to the entire glenoid and the majority of the humeral head (except caudomedial in adult, heavily muscled horses). The described arthroscopic and instrument portals allowed access to the areas frequently affected with osteochondritis dissecans (OCD). Potential difficulties with this technique include problems establishing triangulation, extravasation of fluids, and inability to reach potential lesions on the caudomedial humeral head with conventional equipment in heavily muscled horses.