Supraspinatus and biceps brachii tendinopathy in dogs

Calcifying tendinopathy was seen on radiographic views of the scapulohumeral joint in 12 of 183 (7 per cent) dogs reviewed retrospectively. Calcifying tendinopathy was identified only in large breed dogs, five being labradors. All the affected dogs, except one, were presented for unilateral thoracic limb lameness, which was typically of a chronic and intermittent pattern. Pain on manipulation of the scapulohumeral joint in the lame leg was present in eight of 12 dogs (67 per cent). Calcification of the supraspinatus tendon was seen in eight dogs and calcification of the biceps brachii tendon was seen in the other four dogs. Radiographic changes indicative of biceps brachii tendon avulsion were found in conjunction with calcification of the contralateral biceps brachii tendon in two dogs. Filling defects, indicative of bicipital tenosynovitis, were also seen in positive contrast arthrograms of two dogs with biceps brachii calcification. Of the eight dogs for which radiographic views of both scapulohumeral joints were available, six dogs had bilateral radiographic signs of calcifying tendinopathy. Overall, radiographic signs of calcifying tendinopathy were seen in 18 scapulohumeral joints, but lameness was apparent in only nine limbs, suggesting the lesion may at times be asymptomatic. Further prospective investigation of calcifying tendinopathy is needed to determine why lameness does not always appear to be associated with the presence of the lesion.