Abstract
Aim: The purpose of this study is to define the hip anatomy in cerebral palsy in a three dimensional geometrical manner and then perhaps plan a better surgical reconstruction for these affected hips.
Materials & Methods: The case notes and radiographs of 18 patients with cerebral palsy who underwent plain radiographs, axial CT and 3D CT scans from October 1993 to June 1995 were reviewed prospectively all being consecutive. The following indices were measured – acetabular anteversion (AA), anterior axial acetabular index (Anterior AAI), posterior axial acetabular index (Posterior AAI), Total axial acetabular index (Total AAI) and acetabular depth/femoral head diameter (AD/FHD) ratio.
Results: The acetabular index, and CEA angle clearly showed the hips to be dysplastic in frontal plane. FAV measurements done on CT scan in our study was 330 on the right and 420 on the left. This was significantly higher than normal in our group of patients. Acetabular anteversion was higher in our series, which contributed to hip instability. There were no patients with acetabular retroversion. The axial acetabular indices suggested predominant anterior than posterior acetabular dysplasia, and the total AAI was suggestive of a flatter and shallower acetabulum. A normal to minimally increased AAI in our study suggests an increase in the size rather than a true malrotation.
Conclusions: Our study shows that CT scan analysis is a useful tool in preoperative planning for hip reconstructions. This analysis gives a better idea of the distorted anatomy and a more accurate quantitative and qualitative assessment of the hips.
The abstracts were prepared by Editorial Secretary, Mr Robin W Paton. Correspondence should be addressed to BSCOS at the Royal College of Surgeons, 35– 43 Lincoln’s Inn Fields, London WC2A 3PN
