The fibular retinacula (also known as peroneal retinacula) are fibrous retaining bands that bind down the tendons of the fibularis longus and fibularis brevis muscles as they run across the side of the ankle.
Fibrous bands, such as the fibular retinacula (also known as peroneal retinacula), secure the tendons of the fibularis longus and fibularis brevis muscles to their respective positions on the lateral side of the ankle.