A novel bi-planar calibration method for digital templating in total hip arthroplasty

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Pre-operative digital templating is crucial for optimizing total hip arthroplasty (THA) and reconstructive orthopedic surgery.
• Accurate calibration is essential to correct magnification effects in radiographic imaging for surgical planning.
• Conventional calibration methods often lack reliability, impacting surgical precision and risk management.

Purpose of the Study:

• To introduce and evaluate a novel bi-planar calibration method for digital templating in THA.
• To reduce calibration errors to below clinically significant levels.
• To assess the method's robustness against common sources of error such as patient rotation and marker displacement.

Main Methods:

• The bi-planar calibration method utilizes two orthogonal radiographs and a radiopaque marker ball.
• A custom algorithm calculates hip plane height relative to the detector.
• Error correction algorithms are incorporated to account for patient rotation and marker positioning.

Main Results:

• The bi-planar method demonstrated potential to reduce calibration errors significantly.
• Quantification of errors showed that without correction, 30° patient rotation caused up to 6.5% error.
• The method theoretically allows correction for clinically relevant rotations (>30°) and marker displacements.

Conclusions:

• The novel bi-planar calibration method shows promise for improving accuracy in THA pre-operative templating.
• This technique may offer superior reliability compared to existing calibration methods.
• Accurate calibration is vital for optimizing surgical outcomes and patient safety in orthopedic procedures.