[Stress test and anatomical study of the lateral collateral ligaments of the ankle]

Many authors have discussed on the instability of the ankle joint. We have therefore investigated the variety, courses and the functions of the lateral collateral ligament by dissecting 16 freshly amputated limbs. It was composed of 4 ligaments, i.e., the anterior talofibular, the posterior talofibular, the calcaneofibular and the lateral talocalcaneal ligaments. These ligaments have various courses and influence the stability of the ankle joint in various manners. Transection of the anterior talofibular ligament alone caused inversion and forward instability, and transection of calcaneofibular ligament alone caused adduction instability of the ankle and subtalar joint, but posterior talofibular and the lateral talocalcaneal ligament and other ligaments, however, played an important role in the stability of the ankle joint, so that injuries of the anterior talofibular ligament or the calcaneofibular ligament caused varying degrees of instability in this joint.

To evaluate this injury the following methods of taking X-ray pictures are indispensable, namely, stress inversion, stress anterior drawer, and stress adduction radiography.