Outcome of surgical management of plano-valgus foot in cerebral palsy with batchelor’s extra-articular subtalar arthrodesis

Introduction: Foot deformities caused by altered or abnormal muscle forces are common in patients with cerebral palsy. The incidence of foot deformities in cerebral palsy is approximately 70% to 90%. The most common deformity is ankle equinus, with equinovarus and equinovalgus deformities being equally common. A foot deformity can have significant effects on the patient's overall ambulatory level. The purpose of this study was to assess the functional outcome of batchelor's extra-articular subtalar arthrodesis in spastic planovalgus foot in cerebral palsy children. Materials and Methods: This is a prospective study of 40 patients (68 feet) with spastic planovalgus foot deformity presenting to BIRRD (T) Hospital from October 2015 to October 2017. Children with spastic planovalgus foot between 6 yrs-14 yrs were included in study. There were 24 male and 16 female children. The mean age at the time of surgery was 10 yrs. Both feet were involved in 28 children, 8 had right foot involvement and 4 had left foot involvement. In our study we had 12 hemiplegics and 28 diplegics. Children with mental retardation, extra pyramidal type of cerebral palsy, rigid plano-valgus foot, spastic quadriplegia were excluded from the study. All patients underwent batchelor's arthrodesis with fibular graft and were immobilized in below knee POP cast for 8 weeks. 24 patients underwent gastrosoleus lengthening along with batchelor's arthrodesis. Clinical and functional outcome was assessed based on AOFAS (American orthopaedic foot and ankle score) clinical rating system. Radiological assessment was done by measuring Lateral talocalcaneal angle and Talar declination angle. The results of batchelor's arthrodesis are stated as satisfactory and unsatisfactory. Satisfactory: Clinical and roentgenographic stabilization of the hind foot and no recurrence of planovalgus deformity. Unsatisfactory: Clinical and roentogenographic evidence of failure of stabilization. Results and Discussion: All children had spastic type of cerebral palsy. Post-operatively children were followed-up for an average period of 14 months, with range from 4 to 24 months. Among 40 patients (68 feet), 8 feet (12 percent) had residual valgus, 12 feet (18 percent) had graft absorption, 4 feet (6 percent) had fracture of the graft and none had varus deformity after an average follow-up of 14 months. Out of 68 feet, 44 feet had “satisfactory” result (65 percent) and 24 feet had “unsatisfactory” result (35 percent). Conclusion: Our experience concludes that batchelor's extra-articular arthrodesis of sub-talar joint is a good procedure for correction of plano-valgus foot deformity in cerebral palsy patients. Advantages of the procedure are simplicity of the technique, immediate firm fixation and early weight bearing.