Hypertrophic peroneal tubercle with stenosing tenosynovitis: the results of surgical treatment.

BACKGROUND: A hypertrophic peroneal tubercle creates a stenotic tunnel which triggers a painful peroneal longus. The painful condition is rare, so delayed diagnosis frequently occurs. The purpose of this study was to retrospectively analyze the diagnosis and the functional results of this condition. MATERIALS AND METHODS: A consecutive series of 6 patients with painful hypertrophy of the peroneal tubercle was surgically treated with simple resection of the peroneal tubercle and tenosynovectomy. There were 4 women and 2 men with a median age of 26 years. The clinical symptoms included a prominence at the lateral calcaneus with tenderness. The symptoms were exaggerated with ankle motion. X-ray and computed tomography scanning revealed a bony prominence at the lateral calcaneal cortex. RESULTS: An enlarged peroneal tubercle and stenosing tenosynovitis were found in all patients. The associated findings included a ganglion cyst in one patient, entrapment of a branch of the sural nerve in one patient, and skin callatosis with bursitis in one patient. After a median follow-up period of 35 months, all patients had achieved satisfactory functional results, which included freedom from pain, good peroneal muscle power, good range of motion of the foot, and no limitation in footwear. CONCLUSION: In summary, the clinical symptoms caused by a hypertrophic peroneal tubercle rarely occurred. However, the diagnosis could be made with careful clinical and radiographic examinations. The symptoms were successfully treated by the complete resection of the tubercle, tenosynovectomy, and early range of motion exercise of the hindfoot joints.