Evaluation of the functional outcome of a percutaneous technique in correction of excessive anteversion in cerebral palsy.

In cerebral palsy, patients' excessive femoral anteversion is one of the most common skeletal abnormalities. The general agreement is concurrent correction of both soft tissue and bony deformities during the same operative setting by combining open femoral derotation osteotomy (FDO) with soft tissue releases. Fifty-one children (75 lower limbs) with cerebral palsy with a mean age of 10.7 years (range 6-16 years) fulfilling the inclusion criteria who underwent percutaneous FDO and when needed customized soft tissue releases. Derotation was maintained by a pin-in-cast technique. The mean follow-up was 24 m (range 14-36 m) and gross motor function classification system, functional mobility scale (FMS) and anteversion angle using the Staheli rotational profile were evaluated. Femoral anteversion was accurately measured by hip ultrasonography followed by a preoperative three-dimensional gait analysis. Preoperative and postoperative data were statistically analyzed to reveal the validity of this method. Internal and external hip rotation improved significantly (P < 0.001, respectively). Mean cast and Schanz screw application time was 49 days and all patients achieved independent walking for at least 5 m within 7 weeks. FMS, ultrasonography measured hip anteversion and gait kinematics also improved significantly (P < 0.01, respectively). Two patients (3.92%) developed a mild knee flexion contracture which resolved completely with physiotherapy at 12 m. The pins-in-fiberglass cast provides sufficient rigid fixation to constitute a reliable and reproducible method permitting early weight bearing. It is versatile enough to allow concomitant soft tissue procedures and correction of other accompanying bony deformities.