A Rare Case of Flexor Digitorum Accessorius Longus Muscle Presenting as Tarsal Tunnel Syndrome

Document Type : CASE REPORT


1 The Orthopaedic Foot and Ankle Unit, Netcare Linksfield Hospital, Johannesburg, South Africa. 2 Department of Orthopaedic Surgery, University of the Witwatersrand, Johannesburg, South Africa


Tarsal tunnel syndrome (TTS) is a relatively uncommon nerve entrapment neuropathy. Many pathologies are reported as
possible causes for TTS. The diagnosis of TTS can be difficult and often missed. We present a rare case of TTS due to
an accessory flexor digitorum longus muscle. Together with a high index of suspicion, MRI is the investigation of choice in
making the diagnosis. These patients are best managed with excision or transposition of the flexor digitorum accessorius
longus (FDAL) and neurolysis of the posterior tibial nerve and its branches.
Level of evidence: IV


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