Are Seating Systems With a Medial Knee Support Really Helpful for Hip Displacement in Children With Spastic Cerebral Palsy GMFCS IV and V?

OBJECTIVE: To evaluate whether medial knee support (MKS) in seating systems aggravates hip displacement in children with cerebral palsy (CP).

DESIGN: Retrospective chart review.

SETTING: Rehabilitation department of tertiary university hospital.

PARTICIPANTS: Children with CP (N=76) using seating systems (intervention group, n=42; mean age 6.86y) and using regular wheelchairs (control group, n=34; mean age 8.15y).

INTERVENTIONS: The intervention group was provided with a seating system with MKS. We enrolled children who did not use a seating system in the control group, retrospectively.

MAIN OUTCOME MEASURES: By radiographic images, Reimer's migration index (MI), lateral center edge angle (CEA), and femur neck shaft angle (NSA) were measured. We compared the demographic data, clinical variables, and radiographs between the 2 groups.

RESULTS: In the intervention group, there was a significant deterioration in the MI, from 26.89% to 44.18% after using the system (P<.001). The progression of MI was 14.72% and 7.82% per year in the intervention and control groups, respectively (P=.016).

CONCLUSION: We should consider the possibility that seating systems with MKS may exacerbate hip displacement in children with CP.