Modified oblique high tibial osteotomy with minimal fixation for correction of adolescent tibia vara: a prospective case series study

PURPOSE: To assess the reliability and efficacy of the modified oblique high tibial osteotomy for correction of complex deformity in adolescent tibia vara. METHODS: A total of 19 patients (25 legs) with adolescent tibia vara were enrolled in this study. There were 16 male (84.2%) and three female (15.8%) patients who had modified Rab oblique osteotomy with minimal fixation performed. The age of the patients at time of surgery ranged from 12 years to 30 years (mean 17.23 (sd 5.27)). The body mass index ranged from 22 kg/m(2) to 42 kg/m(2) (mean 32.05 (sd 6.13)). All patients were followed up for over two years (mean 3.4; 2 to 5). RESULTS: The femoro-tibial angle was improved from -34° to -12° (mean -20.04° (sd 5.24°) preoperatively and from -12° to 7°, postoperatively (mean 2.04° (sd 4.07)). Medial deviation of the mechanical axis corrected from 38 mm to 125 mm (mean 76.13 (sd 23.29)) preoperatively to 0 mm to 36 mm (mean 5.74 (sd 7.3)) postoperatively. The time needed to achieve union ranged from eight weeks to 16 weeks (mean 10.2 (sd 2.42)). According to the Lysholm functional knee score scale, there were 15 excellent (78.9%), two good (10.5%), one fair (5.2%) and one poor (5.2%) after correction of the deformity. CONCLUSION: Modified Rab osteotomy with minimal fixation by two or three screws shows promising results with good correction of varus deformity (coronal plane), internal torsion (axial plane) and procurvatum (sagittal plane), in management of adolescent tibia vara with minimal morbidity and complications. LEVEL OF EVIDENCE: IV