Retinacular disorders of the ankle and foot.

The retinacula of the ankle are distinct structures defined as regions of localized thickening of the crural fascia covering the deep structures of the distal portion of the leg, ankle, and foot. Their role is to maintain the approximation of the tendons to the underlying bone. The retinacula of the ankle and foot contain the extensor retinaculum, the peroneal retinaculum, and the flexor retinaculum. Knowledge of the normal anatomy and imaging appearance of these structures is essential for the depiction of their injuries. Even though they may provide an explanation for chronic and unexplained residual pain after an injury, they are frequently overlooked or misdiagnosed.