Prevalence and predictive factors of hip displacement in children with cerebral palsy at Paediatric Institute, Kuala Lumpur Hospital

ABSTRACT

Objective: We aim to study the prevalence and predictive factors for hip displacement, in order to justify a hip surveillance programme for children with cerebral palsy (CP) in Malaysia. Methods: Children aged 2 to18 years old with CP were recruited from September 2013 till June 2014. The hip joint migration percentage (MP) and acetabular index (AI) were measured on all hip radiographs. The CP subtype was determined and gross motor function was classified according to the gross motor function classification system (GMFCS). Results: Seventy-five children were recruited. Fifty-five percent of them had marked hip displacement with MP > 30% and 15% developed hip dislocation (MP=100%). Marked hip displacement occurred as early as age of 2 years and most hip dislocations were detected by age of 10 years. The risk of marked hip displacement was directly related to the GMFCS level, from none in GMFCS I to 75% in GMFCS V. There was a moderate positive correlation between the initial AI and initial MP. Conclusions: One in every two children with CP was at risk of hip displacement, with GMFCS level and initial AI as significant predictive factors. We recommend a hip surveillance programme for Malaysian children with CP, based on the child’s age and GMFCS level, with both MP and AI as indicators for hip surveillance.