Ultrasound of the Tarsal Tunnel

The tarsal tunnel, situated on the medial side of the ankle, encapsulates several vital structures within its fibro-osseous confines. Its boundaries are demarcated by the flexor retinaculum, a strong band of connective tissue extending between the medial malleolus and the calcaneus. The tarsal tunnel houses the tibial nerve, a major branch of the sciatic nerve, as its primary neural constituent. Alongside the nerve, the tunnel accommodates the posterior tibial artery, posterior tibial vein, tibialis posterior, flexor digitorum and flexor hallucis tendon. These tendons play crucial roles in foot movement and support. The contents of the tarsal tunnel are intricately positioned and surrounded by soft tissues, creating a complex anatomical region. Compression or entrapment of these structures within the tarsal tunnel can lead to various conditions, such as tarsal tunnel syndrome, emphasizing the importance of a detailed understanding of the tunnel’s contents for clinical assessment and management.