Compression of the deep branch of the peroneal nerve by the extensor hallucis brevis muscle: a variation of the anterior tarsal tunnel syndrome.

Anterior tarsal tunnel syndrome is a rare condition in which the deep peroneal nerve is trapped below the extensor retinaculum at the ankle. The authors report a variation of this condition: a 67-year-old woman who had anterior tarsal tunnel syndrome caused by entrapment of the deep peroneal nerve by the extensor hallucis brevis muscle. Conservative treatment was unsuccessful, but surgical decompression of the nerve provided immediate improvement, and by 2 weeks postoperatively she had no residual pain or paresthesia, although there was some numbness in the first web space.