Abstract
BACKGROUND: The purpose of this study was to analyse if there is a relationship between the directions of windswept hip deformity and scoliosis for children with cerebral palsy (CP) and to explore potential associations with spasticity, contractures and hip displacement. METHODS: A cross-sectional registry-based study was conducted using data from the combined Swedish CP Follow-up Program and National Registry, including children aged 0–18 years across all levels of the Gross Motor Function Classification System. Prevalence and direction of windswept hip deformity was assessed based on calculations of passive range of motion in abduction, internal and external rotation of the hips. Scoliosis was defined as either a moderate or severe curve at clinical examination or a radiographic Cobb-angel of ≥ 20°. The direction of scoliosis was determined by the convexity of the spinal curve. RESULTS: A total of 4,453 children (mean age 10.2 years [SD 4.8]) were included. In total 774 (17.4%) had scoliosis (n = 503) or windswept hips (n = 413). Among these141 had both scoliosis and windswept hips allowing for analyses of directional relationships. The scoliosis and windswept hip deformity were going in opposite directions in 75 of the 141 children, and in the same direction in 66 children. More children with scoliosis and windswept hips to the same side had a contralateral hip displacement (p < 0.001). Whereas children with deformities in opposite directions more frequently had a hip displacement contralateral to the windswept hip deformity. The direction of the scoliosis was associated with a contralateral hip displacement (p = 0.020). The direction of the windswept hip deformity was associated with a contralateral hip displacement (p < 0.001), hip flexion contracture (p = 0.002) and spasticity in the hip adductors on the opposite side (p < 0.001). CONCLUSIONS: There is no clear directional relationship between windswept hips and scoliosis in children with CP. However, the direction seems to be highly associated with the location of hip displacement, hip flexion contracture and spasticity of the hip adductors. These findings suggest that preventing and treating contractures in the lower extremities, along with active hip surveillance, may help reduce the development of both scoliosis and windswept hip deformity.