Simplified 3D-evaluation of periacetabular osteotomy

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Biomechanical Engineering

Background:

• Hip dysplasia requires precise surgical planning for effective treatment.
• Traditional 3D-CT reconstructions involve multiple slices and are time-consuming.
• Accurate preoperative assessment of acetabular orientation and displacement is crucial for reorientation osteotomies.

Purpose of the Study:

• To develop and validate a simplified 3D reconstruction method from a single AP pelvic view for preoperative planning of hip dysplasia surgery.
• To compare the accuracy of this novel method with 3D CT-scan reconstruction and anatomical preparations.
• To evaluate the clinical and radiological outcomes of Ganz osteotomy planned with this 3D method.

Main Methods:

• Developed a 3D reconstruction software using a single AP pelvic radiograph, assuming spherical femoral head and acetabulum.
• Compared the novel 3D reconstruction with 3D CT scans and pelvic anatomical models.
• Treated 22 patients (17 female, 5 male) with hip dysplasia using Ganz periacetabular osteotomy, with a mean age of 27 years and mean follow-up of 4.8 years.
• Assessed clinical outcomes using the Charnley scoring system and radiological outcomes including Wiberg, Lequesne angles, and acetabular coverage.

Main Results:

• The 3D reconstruction from a single view showed good correlation with CT scans and anatomical preparations.
• Patients experienced significant improvement in pain (Charnley score from 3.6 to 5.8) and no loss of mobility.
• Radiological improvements included 141% increase in Wiberg angle and 161% in Lequesne angle.
• Acetabular anterolateral coverage improved from 20.3% to 50.1%, with a 28% increase in vertical projection area.
• The method allows for better prediction and control of acetabular displacement during surgery.

Conclusions:

• A simplified 3D reconstruction from a single AP pelvic view is a viable and accurate tool for preoperative planning in hip dysplasia surgery.
• This method facilitates precise control over acetabular reorientation during Ganz osteotomy, potentially improving surgical outcomes.
• While not replicating exact cartilage morphology, the technique offers significant advantages in planning and executing 3D reorientation osteotomies for hip dysplasia.