A randomized controlled trial studying efficacy and tolerance of a knee-ankle-foot orthosis used to prevent equinus in children with spastic cerebral palsy

Abstract

Objective: To examine whether using a knee-ankle-foot orthosis helps maintain ankle-foot dorsiflexion range of motion over time.

Design: A multicentre randomized controlled trial.

Setting: Two hospitals and one rehabilitation centre in the Netherlands and the USA.

Subjects: Children (4-16 years old) with spastic cerebral palsy who were able to walk.

Intervention: Use of a knee-ankle-foot orthosis, equipped with an Ultraflex ankle power unit, for at least 6 hours every other night for one year.

Primary outcome measure: ankle-foot dorsiflexion range of motion.

Secondary outcome measures: ankle-foot and knee angle in gait and gross motor function. Wearing time was also measured. Measurements were taken at baseline and at 3, 6, 9 and 12 months.

Results: 28 children (experimental group: n=15, control group: n=13) participated in the study. 11 participants (experimental: n=4, control: n=7) did not complete all five measurements, as they needed additional treatment. No significant difference was found in the decrease of ankle-foot dorsiflexion range of motion between the experimental and control groups (difference: -1.05°, 95% confidence interval: -4.71° - 2.61°). In addition, secondary outcome measures did not show differences between groups. Despite good motivation, knee-ankle-foot orthosis wearing time was limited to a mean±SD of 3.2±1.9 hours per prescribed night due to discomfort.

Conclusions: Knee-ankle-foot orthosis with dynamic ankle and fixed knee are poorly tolerated and are not beneficial in preventing a reduction in ankle-foot dorsiflexion range of motion in children with spastic cerebral palsy, at least with limited use.

Keywords: Orthotic devices; ankle; cerebral palsy; contracture; equinus deformity; foot; gait; knee; randomized controlled trial; range of motion.