Modified triple pelvic osteotomy for residual acetabular dysplasia through double incisions: Technical note and review of short-term results.

Purpose: To assess validity, safety, and efficacy of the modified triple pelvic osteotomy (TPO) approach for correction of residual acetabular dysplasia.

Methods: This is a retrospective case series conducted on 15 hips in 15 patients from 2019 to 2023 with residual acetabular dysplasia treated by modified TPO as described by Tonnis with two modifications. The first modification is using a single medial incision for pubic and ischial cuts (the Vladimirov modification). The second modification is having the ischial cut closer to the acetabulum (Li modification) allowing free movement of the acetabular fragment for better femoral head coverage. The mean age at the time of surgery was 11.85 years, (range 8-23). Cases presenting were 10 males (66.7%) and 5 females (33.3%). The mean follow-up period was 36.533 months (24-60 months).

Results: Our study revealed significant clinical and radiological improvement. The CE angle improved from a mean value of 10° (range 2-17) pre-operatively to 32.785° (range 18°-40°) post-operatively. The AI improved from a mean value of 32° pre-operatively to a mean value of 13.89° post-operatively. HHS increased from a preoperative mean value of 74.80° to a post-operative mean value of 90.67°. Also, there was a significant improvement in ROM (abduction and internal rotation). LLD improved from a mean value of 2.60 cm preoperatively to a mean value of 0.37 cm postoperatively. Delayed union was found in 3 cases. No cases of osteonecrosis or neurovascular complication were encountered in our study.

Conclusion: The modified TPO technique using dual incisions can be considered safe and effective, providing adequate coverage of the femoral head in acetabular dysplasia with less surgical time, satisfactory functional outcomes, and minimal complications.

Level of evidence: IV.