Tarsalkanalen

Tarsalkanalen, or the tarsal canal, is an anatomical channel located on the medial aspect of the ankle within the tarsal tunnel. It is bounded by the flexor retinaculum as its roof and by the bones of the tarsus, including the calcaneus and talus, as part of its surrounding boundaries. The canal serves as a conduit for structures passing from the leg to the plantar foot.

Within the tarsal canal lie several important structures, notably the tibial nerve and its branches (including the medial and lateral plantar nerves), the posterior tibial artery and vein, and the tendons of the flexor digitorum longus, flexor hallucis longus, and, variably, the tibialis posterior. The tibial nerve often divides into plantar branches within or near the canal.

Functionally, the canal provides a passage for neurovascular and tendinous elements traveling from the leg to the foot, while the flexor retinaculum helps form a protective roof.

Clinical significance arises from the potential compression of the contained structures, a condition commonly referred to as tarsal tunnel syndrome. Causes include overuse, ankle injuries, edema, varicose veins, tenosynovitis, ganglia, or anatomical variations. Symptoms typically involve burning pain, numbness, tingling, or paresthesias on the sole or plantar aspect of the foot, and may be accompanied by weakness of intrinsic foot muscles.

Diagnosis is based on clinical assessment and supported by nerve conduction studies and imaging such as MRI or ultrasound. Treatment ranges from conservative approaches (rest, NSAIDs, orthotics, physical therapy, injections) to surgical decompression with release of the flexor retinaculum to relieve pressure on the canal’s contents.