Early radiological results of femoral varus derotation osteotomy in spastic cerebral palsy

ABSTRACT

The aim of the study was to evaluate the early radiological changes after femoral varus derotation osteotomy [VDRO] in spastic cerebral palsy [CP] patients with hip subluxations and correlating the effects of healing and remodeling of the osteotomy on the containment of the hip on a short term basis. Al-Razi Orthopedic Hospital, Kuwait. We performed a femoral varus d e rotation osteotomy on 17 patients [29 hips] with spastic cerebral palsy presenting with hip subluxations or dislocation. The radiological changes occurring after healing of the osteotomies were followed up for a maximum of 16 months. The radiological assessment included Reimers migration percentage [MI%], femoral neck shaft [FNS] angle and acetabular index [AI]. These parameters were assessed preoperatively, immediate postoperative films, and 14-16 months postoperatively. The results were graded as good, fair and poor. A good result is achieved when the hip is contained, the migration percentage is less than 5%, and the femoral neck shaft angle is from 100-115 degrees. A poor result is achieved when the Reimer's index is > 25% and femoral neck shaft angle is > 130 degrees. Analysis of the results, and the reasons for poor results are presented. Spastic cerebral palsy with hip subluxation may progress to complete dislocation. Femoral VDRO improves the containment of the hip and its stability on a short-term basis. Remodeling at the osteotomy site may cause recurrence of the coxa valga especially in the younger age groups. This recurrence may affect the containment and stability of the hip especially in those patients with high MI% and high AI. To decrease this effect of remodeling of the osteotomy on the containment of the hip, the femoral neck shaft angle at the time of the osteotomy should be kept below 115 degrees. In patients with a high MI% and high AI, VDRO alone does not maintain the hip containment adequately