Histopathological, radiographic, and arthrographic comparison of the biceps tendon in normal dogs and dogs with biceps tenosynovitis.

In dogs surgically treated for biceps tenosynovitis, the most common histopathological findings were fibrosis and collagen degeneration (n=13), synovial villous or vascular hyperplasia (n=10), lymphocytic-plasmacytic infiltrates (n=10), cartilaginous metaplasia (n=8), and ischemic necrosis (n=5). Degree of histopathological changes was associated with degree (p equals 0.000), but not duration (p equals 0.543), of lameness. Furthermore, there was no association between histopathological changes and age or radiographic and arthrographic findings. Cartilage metaplasia was the only histopathological finding in both affected tendons (8/18) and normal control dogs (13/13). Age and size of the control dogs were not determined; however, since all these dogs were clinically normal, fibrocartilaginous metaplasia can be present as an incidental finding in the biceps tendon of origin in dogs.