Asymmetric hip deformity and subluxation in cerebral palsy: An analysis ofsurgical treatment

Thirty-seven cerebral palsy patients were followed with measurements of the migration index (MI), infrapelvic obliquity, and suprapelvic obliquity ove r a mean period of 73 months to evaluate the development of the windblown d eformity. The infrapelvic asymmetry was apparent before the suprapelvic obl iquity; however, 65% eventually had both. The final pattern of infrapelvic obliquity and the most subluxed hip could not be predicted from initial rad iographs or from the pattern of scoliosis. Hip subluxation strongly correla ted with the degree of femoral adduction and weakly with the magnitude of s uprapelvic obliquity. The suprapelvic obliquity and scoliosis increased ove r time and influenced the final windblown appearance. Soft-tissue surgeries did not have a significant effect on the final MI. Severe abduction deform ities generally followed ipsilateral adductor releases. Finally, despite im provement in the MT of the initially more subluxed hip, 33% of patients sti ll had one hip with a MI >50%.