The peroneal retinacula
(singular: peroneal retinaculum
) are fibrous bands which bind down the tendons of the Peronæi longus
and brevis as they run across the lateral side of the ankle
The fibers of the superior retinaculum (external annular ligament) are attached above to the lateral malleolus and below to the lateral surface of the calcaneus.
The fibers of the inferior retinaculum are continuous in front with those of the cruciate crural ligament; behind they are attached to the lateral surface of the calcaneus; some of the fibers are fixed to the peroneal trochlea, forming a septum between the tendons of the Peronæi longus and brevis.