Study design: Epidemiological total population study based on a prospective follow-up cerebral palsy (CP) registry.
Objective: To describe the prevalence of scoliosis in a total population of children with CP, to analyze the relation between scoliosis, gross motor function, and CP subtype, and to describe the age at diagnosis of scoliosis.
Summary of background data: Children with CP have an increased risk of developing scoliosis. The reported incidence varies, partly due to different definitions and study groups. Knowledge of the prevalence and characteristics of scoliosis in an unselected group of children with different CP types and levels of function is important for health care planning and for analyzing the risk in an individual child.
Methods: A total population of 666 children with CP, aged 4 to 18 years on January 1, 2008, followed with annual examinations in a health care program was analyzed. Gross Motor Function Classification System (GMFCS) level, CP subtype, age at clinical diagnosis of scoliosis, and the Cobb angle at the first radiographical examination were registered.
Results: Of the 666 children, 116 (17%) had mild and another 76 (11%) had moderate or severe scoliosis based on clinical examination. Radiographical examination showed a Cobb angle of more than 10° in 54 (8%) children and a Cobb angle of more than 20° in 45 (7%) children. The risk of developing scoliosis increased with GMFCS level and age. In most children, the scoliosis was diagnosed after 8 years of age. Children in GMFCS level IV or V had a 50% risk of having moderate or severe scoliosis by 18 years of age, whereas children in GMFCS level I or II had almost no risk.
Conclusion: The incidence of scoliosis increased with GMFCS level and age. Observed variations related to CP subtype were confounded by the GMFCS, reflecting the different distribution of GMFCS levels in the subtypes. Follow-up programs for early detection of scoliosis should be based on the child's GMFCS level and age.