Stenosing tenosynovitis of the flexor hallucis longus at the ankle joint.

The discussion of stenosing tenosynovitis of the flexor hallucis longus at the level of the ankle joint is not found in the literature with frequency. A thorough understanding of the involved anatomy is necessary when considering this condition. A strong clinical suspicion, coupled with appropriate diagnostic tests, is necessary to arrive at a proper diagnosis. Various treatment options may be considered. However, surgical decompression of the stenosed sheath ultimately is recommended by the authors.