A NATIONAL ANALYSIS OF SURGICAL TREATMENT OF HIP DISPLACEMENT IN CEREBRAL PALSY

Introduction Paediatric patients with cerebral palsy (CP) have higher rates of hip displacement. Surgical strategies vary with the likelihood of repeat procedures remaining a key outcome. We compared paediatric patient characteristics (age, GMFCS, ethnicity, region) with regards to the primary surgical hip procedure and any subsequent surgical procedure, including soft tissue release (STR), femoral osteotomy ± STR, and femoral plus pelvic osteotomy ± STR. Methods Health data for 1,149 patients with cerebral palsy born between 2002-2018 and included on the New Zealand Cerebral Palsy Register were matched to data from the National Minimum Dataset (NMDS, 2002-2023) using the National Health Index (NHI). Procedures were grouped using national coding data and analysed by demographics, GMFCS level, CP type, and region of domicile. Results Overall, 251 of the 1149 patients (22%) had had hip surgery within the first 15 years of life. 182 of these patients (73%) were GMFCS IV–V and had quadriplegic CP. Overall, 72 of the 182 (40%) non-ambulatory children had ≥1 repeat operation, with 44 having one repeat operation, 28 having 3 operations and 8 having 4 operations. Repeat procedure rates were highest in the STR group (45%), followed by femoral (40%) and combined osteotomies (29%). Femoral osteotomy was the most frequent repeat procedure (60%). The median time from index procedure to second operation was 3.8 years. Regional variation was observed in choice of index procedure. Conclusion Patients with non-ambulatory CP undergoing STR alone had an approximately 45% chance of further surgery, slightly higher than those undergoing femoral osteotomies as the index procedure. Patients undergoing femoral and pelvic osteotomy primarily had the lowest rate of repeat surgery. These findings highlight expected revision rates at a national level and could be useful in counselling families on outcomes for this group of patients.