Correction of Bowleg Deformity in Achondroplasia through Combined Bony Realignment and Lateral Collateral Ligament Tightening

Introduction: Achondroplasia is one of the most common osteochondrodysplasias with an incidence of 1 in 26,000 live births. Bowing of lower limbs can cause significant morbidity in this population. The use of the Ilizarov external fixator to tighten collateral ligaments of the knee in children has not been reported in the literature. We report the technique and early results of lateral collateral ligament (LCL) tightening with correction of genu varum in children with achondroplasia. Materials and methods: A retrospective review of children with achondroplasia presenting with bowleg deformity who were treated by corrective osteotomy and LCL tightening was conducted. Between 1998 and 2003, 12 patients (24 limb segments) underwent this procedure and were included in the study. All patients had grade III LCL laxity preoperatively. Pre- and postoperative anteroposterior standing mechanical axis radiographs were evaluated. The final outcome was graded using the grading system of Paley et al. Results: All patients had bilateral corrections.The Ilizarov external fixator was used in 10 patients and the Orthofix limb reconstruction system in 2 patients.The bony realignment was achieved through monofocal or bifocal tibial osteotomies.The LCL was tightened In all limb segments using the Paley's type II strategy. The final result was graded as excellent in 20 limb segments and good in 4 limb segments. One patient developed transient common peroneal nerve palsy, four developed grade II pin site infections, and there was premature consolidation of the tibial regenerate in one patient.