Single-center experience with Knee+™ augmented reality navigation system in primary total knee arthroplasty

BACKGROUND

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. Yet, the accuracy of augmented reality navigation systems has not been determined.

AIM

To examine the accuracy of component alignment and restoration of the affected limb's mechanical axis in primary total knee arthroplasty (TKA), utilizing an augmented reality navigation system and to assess whether such systems are conspicuously fruitful for an accomplished knee surgeon.

METHODS

From May 2021 to December 2021, 30 patients, 25 women and five 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+™ augmented reality 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 Augmented Reality 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.

RESULTS

A statistically significant difference was observed regarding mean expected values and radiographic measurements for femoral flexion measurements only (Z score = 2.67, P value = 0.01). Nonetheless, this difference was statistically significantly lower than 1 degree (Z score = -4.21, P value < 0.01). In terms of discrepancies in the calculations of expected values and controlled measurements, a statistically significant difference between tibial varus values was detected (Z score = -2.33, P value = 0.02), which was also statistically significantly lower than 1 degree (Z score = -4.99, P value < 0.01).

CONCLUSION

The results indicate satisfactory postoperative coronal alignment without outliers across all three different implants utilized. Augmented reality navigation systems can bolster orthopaedic surgeons' accuracy in achieving precise axial alignment. However, further research is required to further evaluate their efficacy and potential.

Incidence of vertebral artery injury in patients undergoing cervical spine trauma surgery in correlation with surgical approach: A review

Spinal cord injuries at the cervical spine level represent the most consequential of the related injuries at all levels of the spine. They can trigger permanent unilateral or bilateral damage with conspicuous disability. Regarding unstable injuries, the gold standard approach is open reduction and osteosynthesis, which can select between anterior and posterior surgical access. Each of the aforementioned approaches demonstrates both advantages and disadvantages; thus, it is up to the surgeon to determine the optimal option concerning the patient's safety. Diligent intraoperative control of anatomical reduction is pivotal to obtaining the best feasible postoperative outcomes. Literature data delineate copious complications following surgical intervention in the cervical spine. Indubitably, the most crucial intraoperative complication accounts for vascular injuries, with the most preponderant being the corrosion of the vertebral artery, as it is potentially life-threatening. This paper aims to provide a succinct and compendious review of the existing literature regarding cervical spinal cord injuries and to deduce many inferences concerning the incidence of iatrogenic vertebral artery injuries in relation to the surgical approach for fracture reduction.