Picture 1: Posterior ankle arthroscopy was performed in a patient with FHL-tendinitis of the left ankle. After complete detachment of the flexor retinaculum from the posterior talar process, the FHL gliding channel remained narrowed. Inspection on the medial side of the tendon revealed two accessory firm retinacular bands running from the medial talar process to the calcaneus. 

Picture 2: Picture showing situation after release of flexor hallucis longus retinaculum, with FHL tendon (1), talus (2) and calcaneus (3). The original location of the flexor hallucis retinaculum is marked (blue).

Picture 3: Picture showing the two accessory bands of the flexor hallucis longus retinaculum (red). These firm accessory bands run from the medial tubercle of the talus to the calcaneus. The arrow points to the subtalar joint, the location of the talar insertion of the resected flexor retinaculum is marked blue.

Video: View the procedure below.