[Biomechanical studies of the lateral collateral ligaments of the ankle using amputated limbs]

In order to study the biomechanical behavior of the lateral ligaments around the ankle joint, strains on the anterior talofibular and the calcaneofibular ligaments were measured under adduction and supination loads. The amount of anterior shift of the talus was also examined under anterior "drawer" force. Specially designed omega-shaped transducers and jig sets to hold a leg and to give various loads to the foot were used for the experiments. Twenty human cadaver specimens of various ages were subjected for the study. The results showed the importance of not only the anterior talofibular ligament but also the calcaneofibular ligament as the stabilizer of the ankle joint and that the calcaneofibular ligament plays an important role in adduction, and the anterior talofibular ligament in both adduction and supination. Transection studies of the ligaments revealed that the calcaneofibular ligament is responsible to some extent for producing positive anterior drawer sign for which, as hitherto considered, the anterior talofibular ligament is the main factor.