Impact of ankle-foot orthoses on static foot alignment in children with cerebral palsy

Background: Children with cerebral palsy who are able to walk are often managed with an ankle-foot orthosis to assist with walking. Previous studies have shown kinematic, kinetic, and energetic benefits during gait with the addition of an ankle-foot orthosis, although the mechanism of this gait improvement is unknown. The ability of orthoses to correct foot malalignment in children with cerebral palsy is not known. The current study was performed to determine the impact of orthoses on static foot alignment in children with cerebral palsy. Methods: A retrospective radiographic review was performed for 160 feet (102 patients). All patients had a diagnosis of cerebral palsy. Standing anteroposterior and lateral radiographs of the foot and ankle were made with the patient barefoot and while wearing the prescribed orthosis and were compared with use of the technique of quantitative segmental analysis of foot and ankle alignment. Results: Analysis of the foot and ankle radiographs made with the patient barefoot and while wearing the brace revealed significant changes in all measurements of segmental alignment (p < 0.05). The magnitudes of these differences were small (< 6 degrees or < 10%) and would be considered clinically unimportant. The coupled malalignment of equinoplanovalgus (clinical flatfoot) showed radiographic correction of at least one segment (hindfoot, midfoot, or forefoot) to within the normal range in 24% to 44% of the feet. The coupled malalignment of equinocavovarus (clinical high arched foot) showed correction of at least one segment to within the normal range in 5% to 20% of feet. Conclusions: The present study demonstrates that the use of the ankle-foot orthoses failed to improve the static foot alignment in the majority of feet in children with cerebral palsy who were able to walk. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.