Multicenter Trial of Proximal Femoral Guided Growth in Children With CP and Hips at Risk of Dislocation (GGSH-MC)

Cerebral palsy (CP) is the leading cause of severe physical disability in childhood, with a prevalence of 1.6 per 1,000 live births in developed countries. Spastic CP, affecting 75% of patients, often leads to progressive musculoskeletal deformities due to muscle imbalance, particularly around the hip joint. Hip dysplasia is the second most common deformity, and if untreated, can progress to dislocation, especially in non-ambulatory children (GMFCS IV-V), where risk exceeds 70%. Hip displacement in CP is attributed to spasticity of the adductors and flexors, growth-related deformities such as coxa valga and acetabular dysplasia, and limited weight-bearing. These changes can impair function, sitting tolerance, hygiene, and quality of life. Current strategies emphasize surveillance and early intervention for hips at risk of dislocation (HRD), including soft tissue surgery. However, recurrence remains high, and reconstructive surgery, while effective, is invasive and associated with significant morbidity. Proximal Femoral Guided Growth (PFGG) is a minimally invasive technique involving medial hemiepiphysiodesis with a cannulated screw to modulate proximal femoral growth and improve containment. Though early outcomes are promising, prospective multicenter evidence is limited. This study is a prospective, multicenter, randomized controlled trial using cluster randomization by center to compare PFGG + standard treatment versus standard treatment alone. Children aged 3-8 years with spastic CP and HRD (MP 30-60%) will be included. The primary outcome is radiographic containment. Secondary outcomes include functional scores, pain, complications, and reintervention rates. Follow-up spans 24 months. All surgeries follow a standardized protocol. Postoperative care includes early mobilization, use of hip abduction wedge, and physical therapy. Sample size is calculated for 80% power to detect a difference in dislocation rates, requiring 42 subjects. Data will be collected using standardized CRFs and managed centrally under SEOP oversight. Adverse events will be systematically recorded. The study has IRB approval and complies with ISO 14155, GDPR, and the Helsinki Declaration. Funding is provided by the 2023 EPOS Research Grant (€10,000). Results will be published regardless of outcome.