Augmented reality navigation improves intraoperative resection accuracy but may not prevent alignment deviations in...

Area of Science:

• Orthopedic Surgery
• Medical Technology
• Biomechanical Engineering

Background:

• Total knee arthroplasty (TKA) aims to restore joint function and alignment.
• Augmented reality (AR) navigation has been introduced to improve surgical precision in TKA.
• Assessing intraoperative versus postoperative alignment is crucial for evaluating TKA outcomes.

Purpose of the Study:

• To compare intraoperative and postoperative coronal, sagittal, and axial alignment in TKA using AR navigation.
• To determine if imperfect implant positioning impacts postoperative alignment following AR-navigated TKA.

Main Methods:

• Retrospective review of 70 TKA cases using AR navigation.
• Assessment of implant positioning on postoperative radiographs to identify adequate vs. imperfect placement.
• Analysis of deviations in key alignment parameters (LDFA, MPTA, HKA, PTS, femoral rotation) between intraoperative and postoperative measurements.

Main Results:

• Significant deviations between intraoperative and postoperative alignment were observed for LDFA (61%), MPTA (60%), HKA (60%), and PTS (67%).
• Most relevant deviations occurred in knees with imperfectly positioned implants (27%), often due to inadequate femoral component impaction (79%) or uneven tibial cement distribution (42%).

Conclusions:

• AR navigation facilitates precise bone resections in TKA but does not inherently reduce alignment deviations.
• Achieving adequate implant positioning in AR-navigated TKA requires meticulous surgical technique, including proper component impaction and uniform cement distribution.
• Accurate bone preparation alone is insufficient for optimal TKA outcomes; surgical diligence in component placement is paramount.