Subtalar Fusion in Cerebral Palsy Patients: Results of a New Technique Using Corticocancellous Allograft

BACKGROUNDValgus deformity of the hindfoot in cerebral palsy (CP) patients is common and causes functional deterioration and shoe fitting problems together with skin ulcerations. Our aims in this study are, to present an intra-articular technique of subtalar fusion using allograft and internal fixation to achieve stabilization and second to report the results and clinical outcome of a series of intra-articular subtalar arthrodesis performed in CP children. METHODSWe performed a retrospective review of radiographs and medical records of 145 children with CP who underwent intra-articular subtalar fusion from January 1994 to December 2004. The subtalar joint was fixed through the anterior facet with a cannulated screw whereas the anterior aspect of the calcaneus was parallel to the anterior aspect of the head of the talus. Tricortical iliac crest allograft was placed into the sinus tarsi and the denuded posterior facet area. Results are grouped as good, satisfactory, and poor according to the radiographic and clinical outcomes. RESULTSThe mean age at the time of surgery was 12.7 years (range5 to 20 y) and the average follow-up was 4.8 years (range2 to 11 y). Good results were obtained in 242 feet (96%). Satisfactory results were obtained in 6 feet (2%) which were painless pseudoarthrosis of subtalar joint in 2 feet and screw removal was required in 4 feet because of pain. Nonunion of thesubtalar joint together with recurrence of deformity was observed in 5 feet (2%) which is accepted as poor result and required revision surgery. No deep infections, implant failure, allograft failure were observed in a mean of 4.8 years. CONCLUSIONSOur described technique of intra-articular subtalar joint fusion is safe and reliable in CP children with high rate of satisfactory results. LEVEL OF EVIDENCETherapeutic studies-Level IV.