Objective:To assess the effectiveness and postoperative stability of proximal femoral varus derotational osteotomy combined with modified triple innominate osteotomy in treating hip dislocation in cerebral palsy.Methods:A total of 28 hips (11 left, 17 right) from 23 patients with cerebral palsy-induced hip dislocation who underwent the said surgical procedures were retrospectively examined between November 2018 and September 2022. The median age at the time of surgery was 7.7 years. Preoperatively, 29% of hips exhibited pain. Intraoperatively, a three-dimensional subtrochanteric osteotomy was performed with internal fixation using a Pediatric Hip Plate, alongside a modified triple innominate osteotomy via the Smith-Petersen and perineal approaches. Clinical assessments included pre- and postoperative evaluations of hip pain and joint mobility, as well as imaging evaluations, including migration percentage, acetabular index, acetabular offset, neck shaft angle, and femoral neck anteversion.Results:With a median follow-up of 15 months (range: 12 months to 20 months), all patients were successfully monitored. The median surgery duration was 6.1 hours, with blood loss averaging 400±153 ml (range 200-800 ml). The difference between the median postoperative (1 week after operative) MP 0% (0%, 0%) and the median preoperative MP 50.5% (38.2%, 75.8%) was statistically significant ( Z=4.624, P<0.001). The difference between the median postoperative AI 1.0° (-3.3°, 11.8°) and the median preoperative AI 29.4° (26.3°, 38.0°) was statistically significant ( Z=4.623, P<0.001). The difference between the median postoperative AO 69.8 (66.0, 76.0) mm and the median preoperative AO 72.3 (69.1, 81.1) mm was statistically significant ( Z=4.099, P<0.001). The difference between the median postoperative NSA 124.3° (118.7°, 129.9°) and the median preoperative NSA 145.6° (139.6°, 153.5°) was statistically significant ( Z=4.541, P<0.001). The difference between the median postoperative FNA 13.0° (5.4°, 24.1°) and the median preoperative FNA 33.6° (27.8°, 39.8°) was statistically significant ( Z=4.407, P<0.001). The pain was relieved postoperatively in 7 hips (88%) and residual hip pain in 1 hip. The postoperative range of motion was preserved. No case of avascular necrosis of the femoral head was observed. There were 2 hips (7%) with nonunion in the iliac arcuate line. No case of redislocation was observed at the last follow-up, and no revision was performed recently. There was no significant difference between the median MP at the last follow-up of 0% (0%, 10.0%) and the median postoperative MP ( Z=0.561, P=0.575). Conclusion:The modified triple innominate osteotomy proved to be an effective intervention for correcting acetabular deformity in cerebral palsy-induced hip dislocation. The combination of proximal femoral varus derotational osteotomy with the modified triple approach not only significantly corrected hip dislocation but also alleviated pain and maintained joint mobility in pediatric patients with cerebral palsy.