Vacuum phenomenon associated with osteochondrosis of the scapulohumeral joint in dogs: 100 cases (1985-1991).

The vacuum phenomenon was visualized in 20 of 100 scapulohumeral joints with osteochondritic lesions in 65 dogs. The phenomenon was associated with the finding of a cartilage flap, lack of joint effusion, and clinical signs of pain and lameness. The vacuum phenomenon was not observed on radiography of 30 clinically normal contralateral joints, and it could not be induced in 36 clinically normal scapulohumeral joints radiographed under stressed extension.