The accuracy of image-guided knee replacement based on computed tomography

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Medical Imaging

Background:

• Total knee arthroplasty (TKA) relies on precise component alignment for optimal function and longevity.
• Traditional alignment methods can be subject to variability.
• Image-guided surgery offers potential for enhanced accuracy in orthopedic procedures.

Purpose of the Study:

• To evaluate the accuracy of a computed tomography (CT)-based image-guided system for femoral and tibial bone preparation in total knee replacement.
• To assess the system's ability to achieve accurate component alignment compared to the mechanical axis.

Main Methods:

• The accuracy of a CT-based image-guided system was evaluated using nine cadaveric limbs.
• Femoral and tibial bone preparation accuracy was assessed via direct measurement with an extramedullary alignment rod.
• Angular errors in the coronal plane were measured without the use of radiographs.

Main Results:

• The mean angular error for femoral preparation was 0.3 degrees.
• The mean angular error for tibial preparation was 1.1 degrees.
• The CT-based system achieved alignment with less than 1 degree error for the femoral component and less than 3 degrees for the tibial component.

Conclusions:

• The CT-based image-guided system provides highly accurate bone preparation for total knee replacement.
• Standardization of knee replacement surgery using this system may enhance the long-term survival of total knee arthroplasty.
• The system's precision in component alignment supports its potential for improving surgical outcomes.