Hip displacement in relation to age and gross motor function in children with cerebral palsy

Area of Science:

• Orthopedics
• Pediatric Neurology
• Rehabilitation Medicine

Background:

• Hip dislocation is a significant complication in children with cerebral palsy (CP).
• Early detection and intervention, through radiographic screening and prophylactic surgery, can prevent most dislocations.
• The Swedish CP registry (CPUP) facilitates annual radiographic monitoring for children with CP at Gross Motor Function Classification System (GMFCS) levels III-V.

Purpose of the Study:

• To assess the risk of hip displacement in relation to GMFCS levels and age in children with CP.
• To analyze data from the CPUP registry to understand hip displacement risks.

Main Methods:

• Followed 353 children with GMFCS levels III-V from age 2-7 years, with initial screening before age 3.
• Recorded annual migration percentages (MPs) using 1,664 pelvic radiographs.
• Employed discrete time survival analysis to evaluate hip displacement risk.

Main Results:

• Children at GMFCS level V exhibited a significantly higher risk of hip displacement throughout the study period (p < 0.05).
• The highest risk was observed between 2-3 years of age, decreasing significantly with age (OR = 0.71).
• By age 7, the cumulative risk of MP ≥ 40% was 47% for GMFCS V, 24% for GMFCS IV, and 23% for GMFCS III.

Conclusions:

• GMFCS level V is associated with a substantially elevated risk of hip displacement compared to GMFCS III-IV.
• The risk of hip displacement peaks in early childhood (2-3 years) and declines with age.
• Supports implementing surveillance programs with radiographic hip examinations for suspected severe CP.