Published online Mar 18, 2024. doi: 10.5312/wjo.v15.i3.247
Peer-review started: October 29, 2023
First decision: December 19, 2023
Revised: January 15, 2024
Accepted: March 4, 2024
Article in press: March 4, 2024
Published online: March 18, 2024
Computer-assisted systems obtained an increased interest in orthopaedic surgery over the last years, as they enhance precision compared to conventional hardware. The expansion of computer assistance is evolving with the employment of augmented reality (AR). With the implementation of navigation systems, orthopaedic surgeons can precisely track and visualize surgical instruments in real-time, conforming to the anatomical structures. Yet, the accuracy of AR navigation systems has not been determined. This case series endeavors to scrutinize the accurateness of component alignment and restoration of the affected limb’s mechanical axis in primary total knee arthroplasty (TKA), employing the Knee+™ system. Additionally, this study aims to evaluate whether such systems are substantively beneficial for a high-experienced knee surgeon.
This study aims to examine the accuracy of component alignment and restoration of the affected limb’s mechanical axis in primary TKA, utilizing an AR navigation system and to assess whether such systems are conspicuously fruitful for an accomplished knee surgeon. Our study denotes the reproducible accuracy of an AR system (Knee+™, Pixee Medical) in 30 TKA patients compared to their intraoperative measurements, which is one of the largest clinical studies of this size to examine the accuracy and efficacy of this system. AR solutions can potentially decrease the outcome dependence on the surgeon’s parameters by providing preoperative planning in the surgeon’s field of view or even indicating impeccable trajectories for placing implants with overlays. In particular, the Knee+™ AR system equips the surgeon with a thorough preoperative plan projected in real-time concerning the alignment of bone components and mechanical axis restoration.
The results indicate satisfactory postoperative coronal alignment without outliers across all three implants. The procedure was performed comfortably and repeatedly by the same team. AR navigation systems can bolster orthopaedic surgeons’ accuracy in achieving precise axial alignment. With regard to the rigorous limits and standards employed for the goals of our study, it is vitally important to emphasize that a difference of 1˚ in final implants’ position is unlikely to be clinically significant, as numerous studies have demonstrated that differences in coronal alignment after TKA of up to 3˚ (or even up to roughly 6˚) result in good clinical outcomes
From May 2021 to December 2021, 30 patients, 25 women and 5 men, underwent a primary unilateral TKA. Revision cases were excluded. A preoperative radiographic procedure was performed to evaluate the limb’s axial alignment. All patients were operated on by the same team, without a tourniquet, utilizing three distinct prostheses with the assistance of the Knee+™ AR navigation system in every operation. Postoperatively, the same radiographic exam protocol was executed to evaluate the implants’ position, orientation and coronal plane alignment. We recorded measurements in 3 stages regarding femoral varus and flexion, tibial varus and posterior slope. Firstly, the expected values from the AR system were documented. Then we calculated the same values after each cut and finally, the same measurements were recorded radiologically after the operations. Concerning statistical analysis, Lin’s concordance correlation coefficient was estimated, while Wilcoxon Signed Rank Test was performed when needed.
A Wilcoxon Signed Rank Test was performed to determine whether there was a statistically significant difference re
Our study aimed to denote the reproducible accuracy of an AR system (Knee+™, Pixee Medical) in 30 TKA patients compared to their intraoperative measurements. At this time, to the best of our knowledge, this is one of the largest clinical studies of this size to examine the accuracy and efficacy of this system, but the first to include implants with different characteristics. The results indicate that good varus/valgus alignment was accomplished without outliers, whilst sagittal alignment was generally featured satisfactory, while the procedure was performed comfortably and repeatedly by the same team. AR solutions can potentially decrease the outcome dependence on the surgeon’s parameters by providing preoperative planning in the surgeon’s field of view or even indicating impeccable trajectories for placing implants with overlays. Diminishing cutting errors is the challenge of every AR system assisting TKA. The Knee+™ AR system equips the surgeon with a thorough preoperative plan projected in real-time concerning the alignment of bone components and mechanical axis restoration. It is a user-friendly system with an effortless intraoperative setup that guides the surgeon throughout the surgery and is versatile in amending operative plans if necessary. Further research is required to evaluate their efficacy and potential.
In the future, it will distinctly possibly serve as a transcendent human-computer interface, enabling dexterous surgeons to attain superior results. Nonetheless, further technological and medical research is requisite to achieve AR technologies' maximum potential and cost-effectiveness. Until then, it is vitally important for the orthopaedic surgeon to rely on their training and adroitness for decision-making and opting wisely to employ an AR system.