[Indications for surgery in ruptures of ankle joint ligaments (author's transl)].

X-ray films of the forced extreme joint position are required for diagnosis of lateral ligamentous injuries of the ankle joint. These x-ray films must be taken in forced extreme joint position in two planes (a.p. and lateral planes) by means of a special holding device simulating the mechanism of trauma by supination, inversion and adduction of the ankle joint by plantar flexion of the foot. If there is a 5 degree difference in talar tilt angle or a 5 mm difference in talar subluxation, an operation is indicated to prevent post-traumatic weak ankle and early arthrosis following chronic instability.