Synovitis in chronically unstable ankles

Histopathologic synovial changes were studied prospectively in 69 patients with 75 ankles operated on for radiographically verified chronic lateral instability. The median duration of instability was 2(0.5-20) years. Before the operation, 73 ankles were painful. After a peroneus brevis tenodesis, all but 1 patient felt improved. Twenty-eight of 75 ankles had moderate or extreme degrees of synovitis. The degree of ankle instability did not influence the severity of changes. Factors that influenced the degree of synovitis were duration of instability of more than 4 years, degenerative changes--such as old bony avulsions, chondral fibrillations and clefts--and high activity level of the patient. To improve stability, alleviate pain, and perhaps to prevent the development of arthrosis, we recommend ligamentous repair in painful active patients with long-standing lateral instability of the ankle with degenerative changes in or around the ankle joint.