RESUMEN
INTRODUCTION: Patients with spastic cerebral palsy GMFCS I-III often develop gait dysfunctions. One of the most prevalent gait dysfunctions is the intoeing gait. Femoral derotation osteotomy is the common treatment for internal rotation gait in cerebral palsy. We now present 3D-gait analysis data of the hip rotation in gait before and after femoral derotation osteotomy. We analysed the influence of the age at the index operation on the risk of recurrence and the surgical technique. METHODS: We included 48 patients treated with femoral derotation osteotomy during a single event of multi-level surgery. Mean hip rotation in standing was measured before and after femoral derotation osteotomy (FDO). The patients were divided into two groups of different age and in a second analysis into two groups with the osteotomy in different locations, either inter-trochanteric (DO proximal) or supracondylar (DO distal). RESULTS: Age at FDO and surgical technique had no influence on the results. However, the variance of the results was very high. Differences were found in the walking speed between the DO proximal and DO distal groups. The walking speed in the group of distal femoral osteotomy was higher. This difference was not significant, but there was a trend to proximal osteotomy in slower walkers. Significant improvements in IRG after FDO were found in our investigation. Our results indicate that FDO as a part of single-event multilevel surgery SEMLS provides a satisfactory mean overall correction of IRG. The results were independent of the age at the index operation and the location of the osteotomy.