Distraction Osteogenesis for Complex Foot Deformities: U-Osteotomy with External Fixation

Background: Certain complex foot deformities can be corrected surgically with a U-osteotomy. This osteotomy is indicated for patients with a uniform deformity of the entire foot relative to the tibia, preexisting stiffness and/or fusion of the subtalar joint, and a pain-free ankle joint. The goal is to create a plantigrade foot through gradual osseous repositioning of the entire foot relative to the tibia by means of external fixation. If needed, foot height can be increased simultaneously. Methods: Fifteen complex multiplanar foot deformities in fifteen patients were treated with a U-osteotomy and gradual correction by means of external fixation. Deformities resulted from congenital causes (seven), trauma (three), and developmental causes (five). The mean patient age at the time of surgery was twenty years (range, four to sixty-three years). The mean duration of external fixation was five months (range, three to eleven months). The mean duration of follow-up was five years (range, three to nineteen years). Clinical and radiographic results were assessed. Results: Osseous union and a plantigrade foot were achieved in all fifteen patients. Seven complications related to the U-osteotomy occurred in four patients, including deep pin-track infection in two, premature osseous consolidation in two, postoperative tarsal tunnel syndrome in two, and peroneal nerve entrapment in one. When comparing the preoperative and final postoperative radiographs, three significant differences were observed: the calcaneotibial angle changed by a mean of 18 degrees valgus (range, 6 degrees to 40 degrees valgus) (p = 0.003), the calcaneus was translated posteriorly by a mean of -8 mm (range, -2 to -20 mm) (p = 0.001), and foot height increased by a mean of 20 mm (range, 3 to 40 mm) (p < 0.001). Fourteen patients were able to walk without supports or assistance; one used only one cane or crutch to walk. Conclusions: U-osteotomy with gradual correction by means of external fixation can be used to obtain a plantigrade foot in patients with complex multiplanar deformities of the foot relative to the tibia.