Periacetabular Osteotomy (PAO): the Contribution of Preoperative Planning Illustrated Through an Animated Case

Periacetabular osteotomy (PAO) is a demanding surgical procedure in which every decision, made both preoperatively and in the operating room, directly influences the final balance and long-term function of the hip.

Today, we are pleased to present, in the form of an animation, a PAO case performed in collaboration with Dr Marquez-Lara, highlighting the importance of preoperative preparation in this type of procedure.

Understanding the Objective of PAO

The primary objective of this PAO was to correct the orientation of the acetabulum in order to improve femoral head coverage and preserve long-term hip function.PAO remains a highly technical surgery, requiring precise bone cuts as well as careful management of the mobile acetabular fragment. Once the osteotomies are completed, the repositioning of the acetabular fragment represents a key step in the procedure.

The Key Role of 3D Planning

Preoperative preparation was based on detailed 3D planning, enabling precise definition of the cutting planes and anticipation of the intended correction prior to surgery.

This planning made it possible to:

• Define the target correction in terms of acetabular orientation and coverage

• Identify sensitive anatomical areas to be preserved

• Secure the sequence of surgical steps around the pelvis

The planning thus serves as the reference framework on which the entire procedure is built.

Patient-Specific Cutting Guides

Based on this planning, patient-specific cutting guides were designed to support the execution of the osteotomies.

These guides helped to:

• Respect the planned orientation and depth of the cuts

• Provide stable and reproducible references

• Facilitate certain freehand steps through clearly identified anatomical landmarks

They contribute to securing a critical phase of the procedure while allowing the surgeon the necessary freedom in the execution of the surgical gestures.

The Aligning Guide: a Key Step in Acetabular Repositioning

Following the osteotomies, repositioning the acetabular fragment represents a decisive phase of PAO.

The patient-specific aligning guide, designed based on the preoperative 3D planning, supports this step by enabling reproduction of the planned fragment orientation, controlling its mobilization, and temporarily maintaining the corrected position during fixation.

Collaboration at the Heart of the Project

We would like to warmly thank Dr Marquez-Lara and the entire surgical team for their trust and for sharing this case. This type of collaboration allows us to continue developing solutions tailored to the requirements of complex surgical procedures such as PAO.