Role of the peroneal tendons and superior peroneal retinaculum as static stabilizers of the ankle.

The role of the peroneal tendons as static stabilizers of the ankle is poorly understood. Anterior-posterior displacement of the talus was evaluated in eight fresh-frozen cadaveric ankle joints. With the distal tibia stabilized, loads of 150 N were applied to the talus in the anterior direction while the ankle was held in neutral. All tests were initially performed on intact specimens. Loads were reapplied after sequential sectioning of the peroneal tendons and superior peroneal retinaculum and then the anterior talofibular ligament. When compared with intact ankles, releasing the peroneal tendons caused an average increase of 15% displacement (0.90 mm, p < .05). Adding the release of the anterior talofibular ligament increased the anterior displacement an additional 16% (1.35 mm, p < .05) for a combined anterior laxity of 34% (2.25 mm, p < .05). The data suggest that the peroneal tendons along with the superior peroneal retinaculum provide static resistance to anterior talar displacement with the ankle in neutral. This may contribute to the overall stability of the lateral ankle not previously recognized.