Radiological and muscular status following injury to the lateral ligaments of the ankle. Follow-up of 144 patients treated conservatively.

An average of 4.2 years after conservative treatment of injury to the lateral ligaments of the ankle 144 patients attended a follow-up examination which included radiography and measurement of the strength of plantar flexion. Prior to treatment all of the patients had a difference in talar tilt of 6 or more degrees between the injured and uninjured side. At follow-up there was instability in 28 patients, or 19.4 per cent, but no correlation between instability and residual symptoms. Nine patients had an anterior "drawer sign" exceeding 2 mm, but this was also without relation to residual symptoms. Radiological evidence of osteoarthrosis was found in five patients, but four of them had a stable ankle joint and only one had residual symptoms. The mean age of the patients with osteoarthrosis was twice that for the entire material. Two patients had osteochondritis of the talus. The strength of plantar flexion was measured in 124 patients. There was significantly less strength in the injured than in the uninjured leg, but there was no statistically significant correlation between residual symptoms and reduced strength or between radiological instability and reduced strength. According to the results of the present study and a previous one (Hansen et al. 1979) and to the results reported in the literature, we find no reason to alter our present principles regarding the diagnosis and conservative treatment of injury to the lateral ligaments of the ankle.