Extrinsic compression neuropathy of the tibial nerve secondary to accessory soleus muscle in a young teenager.

Compression neuropathy of the tibial nerve or one of its terminal branches (tarsal tunnel syndrome) is relatively uncommon. Accessory musculature on the posteromedial aspect of the ankle is a rare extrinsic cause of compression. Therefore, it should be considered in patients with prolonged manifestations of tibial nerve compression. A detailed history and physical examination, together with proper radiological evaluation, allow for accurate diagnosis. In this case report, a 13-year old female teenager on history, physical examination, and imaging studies was diagnosed as compression neuropathy of the tibial nerve secondary to accessory soleus muscle. After surgical excision of the accessory soleus muscle with no tarsal tunnel release, the patient presented with complete resolution of her manifestations continued free of symptoms for one and half year postoperatively. The accessory soleus muscle is a potential extrinsic cause for tibial nerve compression neuropathy. LEVEL OF CLINICAL EVIDENCE: 5.