The superior extensor retinaculum is a transverse fibrous band across the anterior ankle approximately 5 cm above the ankle joint, connecting the tibia to the fibula and constraining the extensor tendons (tibialis anterior, EHL, EDL, and peroneus tertius) within their compartments. Unlike the inferior extensor retinaculum (which forms fibrous tunnels for each tendon), the superior retinaculum is a single broad band without individual compartments.
Prevents bowstringing of the extensor tendons during ankle dorsiflexion; maintains the extensor tendons in close apposition to the anterior ankle and lower leg; compresses the tendons and their sheaths to prevent dislocation during powerful ankle extension.
The superior extensor retinaculum is relevant in anterior tarsal tunnel syndrome: the deep peroneal nerve compressed under the retinaculum produces anterior ankle pain and dorsal foot sensory loss. The retinaculum is divided in fasciotomy for anterior compartment syndrome, releasing the extensor compartment pressure. In anterior ankle impingement, osteophytes on the anterior tibia and talar neck (footballer's ankle) protrude beneath the retinaculum, causing impingement during ankle dorsiflexion. Anterior extensor retinaculum release with anterior ankle arthroscopy addresses both osteophyte impingement and any retinacular contribution to nerve compression.
The superior extensor retinaculum may contribute to anterior tarsal tunnel syndrome by compressing the deep peroneal nerve as it passes beneath the retinaculum at the anterior ankle; release of the retinaculum and the inferior extensor retinaculum decompresses the nerve throughout its anterior ankle course.
