Factors associated with hip deformity in children with nonambulatory spastic cerebral palsy

Hip deformities, including subluxation, dislocation, and coxa valga, are common in nonambulatory children with spastic cerebral palsy (CP), especially those classified as Gross Motor Function Classification System IV and V. These deformities impact daily activities and quality of life. This study aimed to identify factors associated with hip deformity and explore rehabilitation strategies to prevent complications. A cross-sectional study (August 2018–May 2020) included 46 children with spastic CP (Gross Motor Function Classification System IV-V, aged 2–10 years). Radiographic and physical measurements, including range of motion, spasticity, muscle strength, and surface electromyography, were analyzed using multiple regression and Pearson correlation. Hip deformities were assessed via Reimer’s migration index, femoral neck-shaft angle, acetabular index, and pelvic obliquity. Migration index was negatively correlated with hip abduction range of motion (ROM) at 90-degree flexion. The femoral neck-shaft angle showed a negative correlation with the abductor-to-adductor muscle strength ratio. These findings suggest that reduced hip abduction ROM and muscle strength imbalance are associated with hip deformities in nonambulatory children with spastic CP. Hip abduction ROM and muscle strength balance are crucial for preventing hip deformities in nonambulatory children with spastic CP. While strengthening hip abductors and improving ROM may be potentially beneficial, interventional studies are needed to confirm whether these strategies reduce subluxation risk. Early identification using noninvasive methods like ROM and surface electromyography can help minimize radiation exposure from frequent radiographic evaluations.