The aim is to describe the characteristics of children with cerebral palsy in Denmark. Furthermore, we want to focus on status of the children's hips.

Introduction: In 1994, a surveillance programme for children with Cerebral Palsy called the Cerebral Palsy Follow-Up Programme (CPUP) was established in Sweden with the primary purpose of preventing hip dislocation.

Hip dislocation is a serious complication to cerebral palsy, which is very painful for the child and requires complex hip surgery. Research studies have documented the effects of the follow-up program on the prevention of dislocation of the hip in children with CP in Sweden.

In 2003, the region of Southern Denmark introduced the Swedish follow-up program with the Danish name Cerebral Palsy Follow-up Program (CPOP). CPOP has since become a national follow-up program as well as a national clinical quality database in Denmark that includes children with CP aged 0-15 years and children with cerebral palsy-like symptoms aged 0-5 (5). The objective of the CPOP is to prevent complications associated with CP such as hip dislocation, scoliosis and contractures of muscles and joints.

It is now ten years since the first children were included in CPOP. There is no report describing the characteristics of children with cerebral palsy in Denmark and the status of the primary aim of the programme, hip status.

This study includes children diagnosed with CP born 2003 - 2020 and registered in the Danish Cerebral Palsy Follow-up Program.

Variables that will be analyzed are:

• age,
• Gross Motor Function Classification System Level I-V
• cerebral palsy subtype,
• Acetabular index,
• standing function,
• range of motion (hip abduction, hip extension, hip external rotation, hamstrings length)
• Modified Ashworth Scale (hip adduction, hip flexion, knee extension)
• Functional Mobility Scare (FMS)
• Gross Motor Function Measure (GMFM)
• hip displacement. Hip displacement is measured using divided into three categories; MP < 33 %, MP > 33-39 % og MP > 40 % with an extra category MP 100% describing children with hip dislocation.
• hip surgery. Categorized as; 1) soft tissue surgery, 2) neurosurgical procedures 3) osseous procedures.

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

Variables will be summarize by counts, proportions and/or percentages using graphs and tables. Furthermore, the median and interquartile range will be specified when meaningful. Additionally, we will do non-parametric statistics (significance tests).

Currently, we do not have information about the extent of missing data for the different variables. When we have obtained the data, we will determine whether we have sufficient completeness for these variables to be included and reported in the statistical significance tests.

Inclusion Criteria:

• Children diagnosed with CP born 2003 - 2020
• Classified at Gross Motor Function Classification Level I to V
• Minimum one radiographic examination of the hips.

Exclusion Criteria:

- Cerebral palsy diagnosis was not confirmed.

Children registered in the Danish Cerebral Palsy Follow-up Program.