Botulinum toxin injections for the treatment of hip instability in the pediatric population with cerebral palsy: a systematic review.

The purpose of this review was to examine the effects of hip muscle botulinum toxin injections for the treatment of hip instability reported in studies of children with cerebral palsy. Searches in PubMed , CINAHL , and Web of Science were performed using the term hips combined with botulinum toxin and its various abbreviations and brand names. Reference lists and citations of the reviewed studies were also searched. Nine studies were reviewed: two randomized controlled trials plus a subsequent long-term follow-up of one of them, and six nonrandomized studies of interventions with two including comparison group(s) and four being single group pre-post studies. Hip adductors were injected in all studies with other hip muscles added in most cases. The outcome measure analyzed was the change in migration percentage defined as postinjection minus preinjection migration percentage with the recommendation of a change of ±10% indicating a true change. Only two studies reported a change exceeding this criterion. One randomized controlled trial demonstrated a 10.4% improvement in the botulinum toxin-treated group, which was statistically significantly greater than a 2.95% worsening in the comparison group. Additionally, a preliminary study of five participants found a statistically significant median change of ≥10% at two of the eight follow-up time points. Therefore, the results of most studies showed neither postinjection improvement nor worsening of this magnitude. The low level of rigorousness of the reviewed studies suggests that any of the results should be viewed cautiously.