Children with cerebral palsy have an increased risk of hip dislocation, which is a painful and severe complication of cerebral palsy. The 20-years evaluation of the Swedish surveillance programme shows that hip dislocation in children with cerebral palsy can be prevented with regular clinical and radiographic examination and early intervention.

We would like to determine the individual risk for hip displacement for Danish children with CP in The Danish Cerebral Palsy Follow-up Program. This could be a valuable clinical tool in deciding on further follow-up and treatment.

Migration percentage (MP) which is measured from the pelvis radiograph is commonly used to assess lateral displacement of the femoral head and is being used in the Swedish and in the Danish surveillance programme. Most children with an MP > 40 % need surgery to prevent further displacement and prevent dislocation of the hip. In the Swedish surveillance programme they have developed the Cerebral Palsy Follow-Up Programme (CPUP) hip score as a risk score to determine which children are at high or low risk for hip displacement (MP > 40 %) within five years after first radiographic examination.

The aim of this study is to predict the likelihood that a child with cerebral palsy will develop hip displacement (MI> 40) within three years. The design is a prediction study.

Data will be obtained from the national clinical quality database the Danish Cerebral Palsy Follow-up Program and the Danish National Patient Register.

Inclusion Criteria:

• Children with cerebral palsy
• Gross Motor Function Classification System III to V
• Migration Percentage < 40 % for both hips at the first pelvic radiographic examination

Exclusion Criteria:

• Previous femoral osteotomy
• Previous pelvic osteotomy
• Previous selective dorsal rhizotomy
• Intrathecal baclofen pump treatment
• Children whose diagnosis was not confirmed
• Children who were no longer followed in the children's ward at the hospital
• Children who moved out of the area
• Children who died during the study period

Children with cerebral palsy in Denmark. Data will be obtained from the national clinical quality database the Danish Cerebral Palsy Follow-up Program and the Danish National Patient Register.