Augmented Reality Navigation Can Achieve Accurate Coronal Component Alignment During Total Knee Arthroplasty.

Area of Science:

• Orthopedic Surgery
• Surgical Navigation
• Medical Technology

Background:

• Computer-assisted orthopedic surgery enhances accuracy in knee arthroplasty.
• Augmented reality (AR) represents the next advancement in computer navigation for total knee arthroplasty (TKA).
• The precision of AR navigation in TKA has not been previously established.

Purpose of the Study:

• To evaluate the accuracy of an augmented reality-assisted navigation system (ARAN) for total knee arthroplasty.
• To assess the coronal and sagittal alignment of bone cuts and component placement using ARAN.
• To identify potential outliers and learning curve effects associated with ARAN implementation.

Main Methods:

• A prospective study of 20 patients undergoing TKA using ARAN between April and October 2021.
• Measurement of femoral and tibial bone cut alignment in coronal and sagittal planes using ARAN.
• Postoperative CT scans were used to verify final component positioning and calculate accuracy.

Main Results:

• 18 cases were analyzed after excluding 2 due to segmentation errors.
• Mean absolute errors for ARAN alignment were: femoral coronal 1.4°, femoral sagittal 2.0°, tibial coronal 1.1°, and tibial sagittal 1.6°.
• No coronal outliers (>3°) were found; however, sagittal outliers were noted for tibial slope and femoral extension, with operative time decreasing significantly over the series.

Conclusions:

• Augmented reality navigation provides accurate alignment in TKA, with a low rate of coronal plane malposition.
• Consistent accuracy is achievable early in the adoption of ARAN, though sagittal outliers indicate areas for improvement.
• A learning curve exists for operative time, suggesting potential for efficiency gains with experience.