Question
A 7 year old boy with spastic quadriplegic cerebral palsy (GMFCS level V) has a migration percentage of 55% in his left hip.
- Why does hip displacement occur in cerebral palsy?
- What is hip surveillance?
- Outline the surgical options.
Answer
Pathogenesis
- Spasticity of the adductors and hip flexors with weak abductors and extensors
- Persistent femoral anteversion and coxa valga
- Progressive acetabular dysplasia, usually posterosuperior
- Risk rises with GMFCS level, reaching up to 90% in level V
Hip surveillance
- Clinical review and AP pelvis radiographs from 12 to 24 months, repeated every 6 to 12 months depending on GMFCS level
- Reimers migration percentage measures the proportion of the femoral head lateral to Perkin line
- Refer for review at a migration percentage over 30%
- Australian Hip Surveillance Guidelines for Children with Cerebral Palsy guide timing
Surgical options
- Preventive soft tissue surgery (adductor and iliopsoas release) for migration 30 to 40% in young children
- Reconstructive surgery with varus derotation femoral osteotomy, pelvic osteotomy such as Dega and open reduction for migration over 40 to 50%
- Guided growth of the medial proximal femoral physis in selected younger children
- Salvage for painful dislocated hips with proximal femoral resection, valgus osteotomy or arthroplasty
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.