Distraction Osteogenesis for Complex Foot Deformities: U-Osteotomy with External Fixation Monique C. Gourdine-Shaw, DPM, Bradley M. Lamm, DPM, Dror Paley, MD, FRCSC, and John E. Herzenberg, MD, FRCSC Investigation performed at the International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital, Baltimore, Maryland 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° valgus (range, 6° to 40° 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. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. D istraction osteogenesis has been used to treat various complex foot and ankle deformities, including those associated with relapsed or neglected clubfoot, fibular hemimelia, arthrogryposis, brachymetatarsia, poliomyelitis, posttraumatic cavoequinovarus, and other congenital defor- mities 1-11 . Ilizarov described many uses and techniques of dis- traction osteogenesis, and he first described the U-osteotomy to correct complex hindfoot, midfoot, foot height, and equinus deformities in 1987 1 . The U-osteotomy is indicated in patients with preexisting stiffness and/or fusion of the subtalar joint, a pain-free ankle joint, and a ‘‘uniform’’ deformity of the foot relative to the tibia (i.e., the forefoot deformity is the same as the hindfoot deformity) 1-9,12 . In such cases, the foot itself does not have any deformities because the forefoot is not deformed relative to the hindfoot. Although the U-osteotomy corrects the position of the entire foot relative to the tibia, it cannot change Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. One or more of the authors, or his or her institution, has had a financial relationship, in the thirty-six months prior to submission of this work, with an entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. No author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article. 1420 COPYRIGHT Ó 2012 BY THE J OURNAL OF BONE AND J OINT SURGERY,I NCORPORATED J Bone Joint Surg Am. 2012;94:1420-7 d http://dx.doi.org/10.2106/JBJS.K.00360