[Involvement of the inner malleolus and deltoid ligament in supination trauma of the ankle joint].

Additional ligament ruptures or fractures of the medial side of the ankle joint accompanying the lateral ligament rupture are rare. These injuries are more often in traumas with pronation-eversion movements of the foot. In cases of lateral ligaments ruptures we only found in 2.8% and in 5.9% additional medial injuries. This is confirmed by different biomechanical experiments. Experimentally the delta ligament rupture could mostly be caused by pronation-eversion movements or by forced plantar flexion of the foot. The diagnosis of bony lesions of the medial malleolus might be easy by X-ray, but ligament lesions of the medial ankle joint can be diagnosed easily too be using the stress X-ray controlling the medial talar tilt as a sign of medial instability. Because the necessity of surgical treatment is less important than of the lateral ligaments we recommend this procedure in cases of bilateral instability or if dislocation is obvious.