Virtual Periacetabular Osteotomy and Anatomical Measurements

Area of Science:

• Orthopedic surgery
• Medical imaging
• Anatomy

Background:

• Periacetabular osteotomy (PAO) is a surgical procedure used to treat hip dysplasia.
• Accurate surgical planning is crucial for successful PAO outcomes.
• Understanding anatomical variations is key to optimizing PAO safety and efficacy.

Purpose of the Study:

• To evaluate the risk associated with different periacetabular osteotomy (PAO) cutting planes using CT scan virtual modeling.
• To compare the safety margins of two distinct retroacetabular cutting (RC) planes in virtual PAO.
• To identify potential anatomical risks and differences between sexes during virtual PAO planning.

Main Methods:

• A virtual periacetabular osteotomy (PAO) was performed on 123 patients (64 male, 59 female) using CT scans.
• Two retroacetabular cutting (RC) planes were defined: the standard RC plane and an RC+ plane positioned 10 mm posterior to the RC plane.
• Key measurements included the distance from the acetabulum to the sciatic notch, the distance to the retroacetabular cutting plane, and osteotomy length.

Main Results:

• Women exhibited significantly smaller distances between the acetabulum and sciatic notch compared to men (24.34 ± 2.92 mm vs. 27.18 ± 3.47 mm).
• The RC+ plane provided a significantly larger distance to the retroacetabular cutting plane (6.97 ± 0.91 mm) compared to the RC plane.
• Both sexes showed significantly shorter osteotomy lengths with the RC+ plane, and all measured parameters were smaller in women than in men.

Conclusions:

• The anatomical safety space for periacetabular osteotomy (PAO) is significantly narrower in women compared to men.
• The RC+ plane, positioned 10 mm posteriorly, offers a safer cutting distance and shorter osteotomy line, reducing the risk of intra-articular penetration during PAO.
• Virtual PAO using CT imaging is a valuable tool for assessing surgical risks and optimizing PAO planning based on individual anatomy and chosen cutting planes.