Prosthetic Alignment and Clinical Outcomes of Navigation-Assisted Unicompartmental Knee Arthroplasty by an Experienced Surgeon Compared With Inexperienced Surgeons

Background: To improve the accuracy of tibial cut during unicompartmental knee arthroplasty (UKA), navigation-assisted UKA has been implemented. It has been reported that inexperienced surgeons who use a navigation system achieve better alignment than experienced surgeons who do not use a navigation system. However, there have been no reports comparing the alignments and clinical outcomes of navigation-assisted UKA performed by experienced surgeons in comparison with that by inexperienced surgeons. This study aims to compare these parameters of navigation-assisted UKA performed by experienced and inexperienced surgeons. Methods: A total of 209 UKA procedures using an image-free navigation system were included. One experienced surgeon performed 128 UKAs (E group), and six inexperienced surgeons performed 81 UKAs (I group). The target value in the coronal tibial plane was set at 2.0 degrees in varus. Prosthetic alignments and clinical results were compared between the two groups. Results: No significant differences were found between the two groups for prosthetic alignments and clinical outcomes, except for range of motion. The operation time of the I group was statistically longer than that of the E group (P<.001). The ratio of tibial prosthetic fracture was significantly higher in the I group than that in the E group (P = .022). Conclusion: Using a navigation system during UKA, inexperienced surgeons achieved accurate alignments and excellent clinical results similar to an experienced surgeon. However, tibial periprosthetic fractures occurred more often in patients of inexperienced surgeons. Even when using a navigation system, inexperienced surgeons need to demonstrate careful and cautious surgical techniques. (C) 2021 Elsevier Inc. All rights reserved.