Background: Although botulinum toxin A is frequently used to augment
serial casting in the treatment of soft-tissue contractures in children with
cerebral palsy, its effectiveness for this purpose has not been evaluated. The
purpose of the present study was to determine whether botulinum toxin A
injection increases the efficacy of serial casting.
Methods: A prospective, randomized trial was undertaken to compare
serial casting only with serial casting combined with botulinum toxin A
(Botox) injection for the treatment of ankle equinus contractures in
twenty-three children with cerebral palsy. Range-of-motion testing, spasticity
assessment, and computerized gait analysis were performed as long as twelve
months after treatment.
Results: There was no difference between the groups with regard to
the duration of casting required to correct the equinus contracture. Both
groups maintained a significant improvement in passive ankle dorsiflexion
throughout the follow-up period, although the group managed with casting and
Botox had a significant loss of dorsiflexion when the values at six, nine, and
twelve months were compared with the value at three months. Peak dorsiflexion
during the stance and swing phases was significantly improved in both groups
at three months but only in the group managed with casting alone at twelve
months. Plantar flexor spasticity was significantly decreased at three months
in both groups, but it was significantly decreased at six, nine, and twelve
months only in the group managed with casting alone. Spasticity was
significantly greater in the group managed with casting and Botox than it was
in the group managed with casting only at six, nine, and twelve months.
Conclusions: The present study demonstrates the efficacy of serial
casting in the treatment of equinus contractures in children with cerebral
palsy who are able to walk. Contrary to our hypothesis, the addition of
botulinum toxin A to a serial casting regimen led to earlier recurrence of
spasticity, contracture, and equinus during gait. The results of the present
study suggest that botulinum toxin combined with serial casting for the
treatment of fixed contractures will lead to a recurrence of plantar flexor
spasticity and equinus contracture by six months in this patient population.
While previous research has indicated that the injection of botulinum toxin A
is superior to casting for the treatment of dynamic equinus, the present study
suggests that serial casting alone is preferable for the treatment of fixed
equinus contractures in children with cerebral palsy.
Level of Evidence: Therapeutic study, Level I-1a
(randomized controlled trial [significant difference]). See Instructions to
Authors for a complete description of levels of evidence.