Longitudinal relationship between hip displacement and hip function in children and adolescents with cerebral palsy: A scoping review

Aim: To identify, describe, and synthesize available evidence on the longitudinal relationship between hip displacement and hip function, using the International Classification of Functioning, Disability and Health (ICF) framework, in children and adolescents with cerebral palsy (CP) aged up to 18years. Method: Five databases were searched systematically from inception to May 2022. Study and sample characteristics, and hip displacement and hip function measures, mapped to the ICF domains, were extracted for narrative synthesis. Results: Twenty-nine studies were included: four longitudinal registry-based studies; 12 prospective studies; 12 retrospective studies; and one randomized controlled trial. Sample size ranged from 11 to 267. Twenty-seven (93%) studies entailed an intervention: surgery (n=16); rehabilitation (n=2); nerve block or botulinum neurotoxin A injection (n=4); and combined surgery and injection (n=2). Twenty-six studies (90%) reported outcomes at the body structure and function and impairment domain of the ICF; 17 (59%) reported outcomes in the activity domain; and three (10%) included participation measures. The most common hip displacement measure was Reimers' migration percentage (79%). Interpretation: Because of the inclusion of interventions in most studies, and the preponderance of retrospective studies, the relationship between hip displacement and hip function in CP is unclear. More high-quality prospective evidence on the natural history of hip displacement, and its effect on function, is needed to improve population-wide screening of children with CP.