Validation of an Augmented Reality Based Functional Method to Determine and Render the Hip Rotation Centre During...

Area of Science:

• Orthopedic Surgery
• Medical Imaging
• Augmented Reality Technology

Background:

• Accurate determination of the functional center of rotation (FCOR) is crucial in total hip arthroplasty.
• Existing methods for FCOR determination can be complex and time-consuming.

Purpose of the Study:

• To present a novel method for determining and visualizing the hip's FCOR using an augmented reality head-mounted display (AR-HMD).
• To evaluate the accuracy and reproducibility of the proposed AR-HMD system in an experimental setting.

Main Methods:

• Developed custom software for a HoloLens AR-HMD to track markers on cadaver femurs and 3D-printed acetabuli.
• Collected 80 measurements by rotating 20 cadaver femurs twice in a matching cup.
• Calculated FCOR based on point cloud data derived from marker displacement relative to acetabular trackers.

Main Results:

• The AR-HMD system achieved an absolute error of 2.9 ± 1.4 mm for the acetabulum and 2.9 ± 1.2 mm for the femur.
• 95th percentile errors were below 5.6 mm for the acetabulum and 4.7 mm for the femur, indicating high precision.
• Demonstrated the system's capability in an experimental setting with cadaveric specimens.

Conclusions:

• The proposed AR-HMD system provides an accurate and reproducible method for determining both femoral and acetabular FCOR.
• This technology has the potential to enhance precision in total hip arthroplasty procedures.
• Further clinical validation is warranted to translate these experimental findings into surgical practice.