Objective: To determine hip radiographic findings in children with cerebral palsy (CP) treated with botulinum toxin type A (BTX-A).
Design: Retrospective chart review with correlation to radiographic findings.
Setting: Academic center.
Participants: Sixteen subjects with CP.
Intervention: BTX-A treatment to adductor muscles.
Main outcome measure: The Reimers hip migration percentage before and after BTX-A.
Results: 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.
Conclusions: 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.