Abstract
PURPOSE: Poor motor control and delayed thumb function and a delay in walking are the main factors which retard the natural decrease of the femoral anteversion (FA) with age. In addition, cerebral palsy (CP) patients usually have muscular imbalance around the hip as well as muscle contractures, both of which are main factors accounting for the increased FA which is commonly present in CP patients. The purpose of this retrospective study was to analyze the mid-term results of femoral derotational osteotomy (FDO) on the clinical findings, temporospatial and kinematic parameters of gait in children with CP. METHODS: We performed a retrospective review of all patients diagnosed with CP and increased FA who were treated with FDO with multi-level soft tissue surgeries at a single institution between 1992 and 2011. FA assessment was done in the prone position, and internal (IR) and external rotation (ER) of the hip was measured in the absence of pelvis rotation. Surgical procedures were performed on the basis of both clinical findings and video analysis. Clinical findings, Edinburgh Visual Gait Scores (EVGS) and results from three-dimensional gait analysis were analyzed preoperatively and last follow-up. RESULTS: A total of 93 patients with 175 affected extremities were included in this review. Mean age was 6.2 ± 3.1 (standard deviation) at initial surgery. The average length of the follow-up period was 6.3 ± 3.7 years. At the last follow-up, the postoperative hip IR had significantly decreased (73.9° vs. 46.2°; p < 0.0001), the hip ER had significantly improved (23.8° vs. 37°; p < 0.0001) and the popliteal angle had significantly decreased (64.2° vs. 55.8°; p < 0.0001). The total EVGS showed significant improvement after FDO (35.2 ± 6.4 vs. 22.5 ± 6.1; p < 0.001). Computed gait analysis showed significant improvement in the foot progression angle (FPA; 8.1° vs. -16.9°; p = 0.005) and hip rotation (-13.9° vs. 5.7°; p = 0.01) at the last follow-up. Stance time was improved (60.2 vs. 65.1 %; p = 0.02) and swing time was decreased (39.9 vs. 35.2 %; p = 0.03). Double support time and cadence were both decreased (p = 0.032 and p = 0.01). CONCLUSIONS: Our data suggest that the FDO is an appropriate treatment strategy for the correction of FA and associated in-toeing gait in children with CP. Improvements in clinical and kinematic parameters were observed in both groups after FDO with multi-level soft tissue release. The most prominent effects of FDO were on transverse plane hip rotation and FPA.