A radiological analysis of lateral ligament injuries of the ankle.

Patients who presented within 5 days of an inversion injury to the ankle joint, were clinically selected for early radiological investigation and diagnosis of rupture of the lateral ligament of the ankle. Stress tenography was performed in 142 cases, and normal ranges for talar tilt and anterior draws were established in 216 normal ankles. In addition 38 cadaveric ankles were examined by peroneal tenography. No normal connection between the tendon sheath and the ankle joint was demonstrated. Sixty-five patients had positive peroneal tenograms; nine of these were positive only after manipulation. No complications occurred. Surgery was performed on 20 patients and demonstrated that common peroneal tenography was 95% accurate in diagnosing rupture of the calcaneo-fibular ligament. Of the 19 patients with proven calcaneo-fibular ligament rupture, six had a positive anterior draw sign, and nine had talar tilt. In this series both the talar tilt and anterior draw signs were found to be inaccurate. Common peroneal tenography is recommended as the method of choice for demonstrating acute rupture of the calcaneo-fibular component of the lateral ligament.