Fast and automatic periacetabular osteotomy fragment pose estimation using intraoperatively implanted fiducials and...

Area of Science:

• Orthopedic surgery
• Medical imaging
• Computer-assisted surgery

Background:

• Accurate 3D positioning of acetabular bone fragments is challenging using traditional fluoroscopy.
• Intraoperative assessment of fragment orientation is critical for successful surgical outcomes.

Purpose of the Study:

• To develop and evaluate a computer-assisted approach for rapid and accurate 3D pose estimation of acetabular bone fragments using a single fluoroscopic view.
• To reduce reliance on manual input and complex imaging setups for intraoperative fragment assessment.

Main Methods:

• Injection of two metallic ball-bearing (BB) constellations into ilium and pubic ramus fragments.
• 3D BB location reconstruction using three fluoroscopic views and CT registration.
• Single-view fluoroscopy for estimating relative fragment pose after osteotomy and relocation.
• Automated BB detection and correspondence computation.

Main Results:

• Mean fragment rotation error of 2.4 ± 1.0 degrees and translation error of 2.1 ± 0.6 mm.
• Mean 3D lateral center edge angle error of 1.0 ± 0.5 degrees.
• Average single-view pose estimation runtime of 0.7 ± 0.2 seconds.

Conclusions:

• The proposed method achieves accuracy comparable to state-of-the-art systems without requiring optical tracking or manual input.
• The system's precision meets the requirements for accurate intraoperative evaluation of femoral head coverage.
• This computer-assisted technique offers a faster and more accessible solution for intraoperative acetabular fragment assessment.