Hip migration percentage in children with cerebral palsy treated with botulinum toxin type A.

Abstract

To determine hip radiographic findings in children with cerebral palsy (CP) treated with botulinum toxin type A (BTX-A). Retrospective chart review with correlation to radiographic findings. Academic center. Sixteen subjects with CP. BTX-A treatment to adductor muscles. The Reimers hip migration percentage before and after BTX-A. Thirty-two hips in 16 children with CP were treated. We examined the effect of initial migration percentage and initial migration percentage age on the change in migration percentage after BTX-A injection. A significant effect for initial migration percentage (<30% or >/=30%; F=19.05, P <.001) and a significant interaction between initial migration percentage and initial migration percentage age (F=7.5, P <.01) was noted. Initial migration percentage age (</=24 mo or >24 mo) was not significant (F=.95, P =.34). Patients who had an initial migration percentage of 30% or more and were less than 24 months old were more likely to have a decrease in migration percentage after BTX-A injection compared with patients who were older than 24 months and who had an initial migration percentage of 30% or more. Improvement in hip migration percentage after BTX-A injection is a function of age and the initial migration percentage. BTX-A injections to adductor muscles may be beneficial for some children with CP.