Lateral instability of the ankle and results when treated by the Evans procedure.

Between 1968 and 1976 81 ankles of 77 patients with lateral instability of the ankle joint were operated on in the Kotka Central Hospital. Sixty patients with 62 ankle surgeries had postoperative followup. The average follow-up time was 5.2 years and the mean age of the patients was 28.3 years. In addition to the interview during the postoperative examination, all patients had anteroposterior (AP) mortice, lateral AP stress, and sagittal stress x-ray films. In the clinical examination ankle joint mobility, stability, peroneal function, predisposition to swelling, and circumference of the calf were investigated. Of the 62 ankles the result was excellent or good in 54 (87%). satisfactory in 5 (8%), and poor in 2 cases (5%). Of the 16 athletes' 18 ankles treated the result was excellent or good in 16 and satisfactory in 2 cases. The Evans procedure prevented talar tilting and gave good stability in anteroposterior direction.