Prevalence of knee contractures is high in children with cerebral palsy in Denmark

Introduction Cerebral palsy (CP) is a neurological disease occurring in children at early gestation, often resulting in pronounced functional limitations. A Swedish cross-sectional study (Cloodt, et al., 2018) discovered that 22% of children with CP had a knee contracture, which was associated with higher levels of Gross Motor Function Classification System (GMFCS), higher age, and higher levels of spasticity measured by the Modified Ashworth Scale (MAS). The current study investigated these associations in a Danish population. Methods This is a cross-sectional study including 1,163 children with CP aged 0-15 years, registered in the Danish National Cerebral Palsy Registry between 2017 and 2019. Prevalence of knee contracture was estimated, and logistic regression analysis was applied with results presented as odds ratio (OR) with 95% confidence intervals (CI). Results A total of 511 children with CP had knee contracture resulting in a prevalence of 44%. Age groups 4-6 years (OR: 1.73, CI: 1.19; 2.52), 7-9 years (OR: 1.85, CI: 1.29; 2.66) and 10-12 years (OR: 2.12, CI: 1.39; 3.24) were significantly associated with a higher prevalence of knee contractures compared to age group 0-3 years. Knee contractures were significantly more frequent at GMFCS levels IV (OR: 1.9, CI: 1.21; 2.97) and V (OR: 3.62, CI: 2.36; 5.55) compared to level I. Knee contractures were not associated with higher levels of MAS. Conclusions Knee contractures are highly prevalent and significantly associated with high levels of GMFCS and increased age until 12 years, but not with high levels of spasticity in children with CP in Denmark.