EP1.29 Anterior Superior Iliac Spine Autograft Technique in Periacetabular Osteotomy: Surgical Description and Early Radiographic Outcomes

Abstract Background The Ganz periacetabular osteotomy (PAO) is the treatment of choice for symptomatic hip dysplasia. Nonunion of one of the osteotomy sites is a known complication, with reported rates ranging from 1% to 17%. Strategies that improve osteotomy healing may reduce this risk. This study describes a surgical technique using an autograft from the anterior superior iliac spine (ASIS) during PAO and evaluates its radiographic outcomes. Purpose To describe a surgical technique utilizing an ASIS autograft during PAO and to report its radiographic outcomes and union rates. Methods A descriptive study was conducted including patients with symptomatic hip dysplasia undergoing PAO incorporating the ASIS autograft technique. All procedures were performed through an oblique inguinal incision with preservation of the rectus femoris origin. The ischial and pubic osteotomies were performed according to the original Ganz technique, with a modification of the third osteotomy beginning at the level of the ASIS. After acetabular reorientation and definitive fixation using 3.5-mm screws, the prominent portion of the ASIS belonging to the reoriented fragment was osteotomized. This bone fragment was prepared and used as an autograft, which was impacted into the defect created at the third osteotomy after correction, positioned over the fixation screws until stable. Demographic variables included age and sex. Radiographic parameters assessed pre- and postoperatively included the lateral center-edge angle of Wiberg, Tönnis angle, and acetabular coverage (extrusion index). Osteotomy healing was evaluated using anteroposterior pelvis and iliac oblique hip radiographs at 2, 4, 6, and 12 months. Descriptive statistics were used for analysis. Results A total of 236 hips were reviewed, of which 150 met inclusion criteria. Mean patient age was 27.3 years and 90% were female. Mean preoperative Wiberg angle was 13.6°, mean Tönnis angle was 18°, and mean acetabular coverage was 65.4%. Postoperatively, the mean Wiberg angle improved to 30.3°, the Tönnis angle decreased to 4.7°, and the extrusion index improved to 83.3%. Mean time to radiographic union was 68 days, with no cases of nonunion observed. Conclusion The use of an ASIS autograft during PAO is a simple technique that provides structural bone grafting at the osteotomy site and was associated with a high rate of osteotomy union in this series.