RESUMO
AIMS: Recurrence of deformity following high tibial osteotomy (HTO) for infantile tibia vara (ITV) is common. The purpose of this study was to identify risk factors for recurrent deformity following HTO for ITV and to develop a simple scoring system to quantify the risk of recurrence in each patient. PATIENTS AND METHODS: We identified 69 patients with 102 affected limbs undergoing HTO for ITV from 2005 to 2015. Demographic and radiographic data was collected. On pre-operative radiographs, we measured the mechanical varus angle (MVA), the condyle shaft angle (CSA), the plateau depression angle (PDA), the metaphyseal-diaphyseal angle (MDA), and the mechanical lateral distal femoral angle (LDFA). On the post-operative radiographs, we measured the MVA and MDA only. We classified each limb according to the Langenskiold and LaMont classifications. Statistical analysis was performed to identify variables predictive of recurrent deformity, and these variables were analysed to develop a scoring system to quantify risk of recurrence following HTO. RESULTS: Of the examined variables, age older than 4.5 years, an MVA of more than 23° and a LaMont type C deformity were predictive of recurrent deformity. The incidence of recurrent deformity increased from 14.3% with no risk factors to 91.3% with three risk factors present. CONCLUSION: Advanced deformity and age above 4.5 years at the time of surgery predicts recurrent deformity following HTO for ITV. Surgery should be performed as soon as possible, and caregivers should be counselled appropriately regarding risk of recurrence and the need for future surgery.
