Congenital Distal Tibiofibular Synostosis: A Case Report of Surgical Management in a Skeletally Immature Patient.

Congenital distal tibiofibular synostosis is quite a rare disease, and little is known about its optimal management. A 6-year-old girl presented to our institution with a deformity of her left lower leg. After years of careful observation, the patient underwent partial resection of a laterally protruding portion of the distal diaphysis of the fibula at age 10 for cosmetic reasons. Since the recurrence of lateral prominence of the distal lower leg was observed following the initial surgery, complete resection of the protruding portion of the distal diaphysis of the fibula was performed at age 14. Although mild varus deformity of the ankle was observed, the ankle joint congruity was good, and there were no associated symptoms or functional limitations. Therefore, we decided to perform a simple resection of the distal fibular diaphysis only for cosmetic improvement. At 1-year follow-up, no recurrence of lateral prominence of the distal lower leg has been observed. There was no difference in ankle range of motion between the left and right sides. The patient reported no pain and was able to participate in sports activities. In patients with preserved ankle function and few complaints about their daily activities, waiting until skeletal maturity and removing only the affected area may provide sufficient outcomes without risking growth potential or ankle function in the treatment of congenital distal tibiofibular synostosis.