Bilateral tarsal tunnel syndrome attributed to bilateral fibrous tarsal coalition and symmetrical hypertrophy of the sustentaculum tali.

Tarsal tunnel syndrome (TTS) is one of the frequently encountered entrapment neuropathies of the lower limb. Most often the aetiology is considered to be idiopathic. However, it has to be thoroughly investigated to rule out diverse extrinsic and intrinsic causes. The sustentaculum tali (ST) forms the superior part of the distal tarsal tunnel, and any increase in its size may result in irritation of the tibial nerve or its branches, the medial and lateral plantar nerves or decrease the overall volume of the tarsal tunnel culminating to clinical features of TTS. A hypertrophied ST is an extremely rare cause for TTS, and we report perhaps a first case of bilateral TTS in a young adult due to bilateral symmetrical hypertrophied ST which in turn was a result of bilateral fibrous tarsal coalition. Staged bilateral surgical excision of the hypertrophied part of ST and the underlying fibrous tarsal coalition ensured prompt symptomatic relief.