The extensor retinaculum is located at the dorsal aspect of the foot and consists of the superior and inferior extensor retinacula.
The superior extensor retinaculum is located proximally to the dorsal aspect of the ankle joint and houses the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius tendons. It also contains the anterior tibial vessels and deep fibular nerve (the superficial fibular nerve passes superficially to it). It originates at the anterior aspect of the distal fibula and attaches medially to the anterior aspect of the distal tibia1.
The inferior extensor retinaculum is Y shaped and is located distal to the superior extensor retinaculum at the dorsal aspect of the foot. The stem of the retinaculum is located at the upper surface of the calcaneus. It then divides into two bands, a proximal limb, attached medially to the medial malleolus, and a distal limb, attached to the plantar aponeurosis. The proximal limb contains a deep and superficial band. It contains the tendons of extensor digitorum longus, extensor hallucis longus, tibialis anterior, and fibularis tertius. It also houses the terminal branches of the deep fibular nerve, and also the dorsalis pedis artery1.