COMPARISON OF MINIMALLY INVASIVE UNICONDYLAR KNEE ARTHROPLASTY WITH OR WITHOUT A NAVIGATION SYSTEM

Abstract

In total knee arthroplasty, navigation systems that help achieve accurate alignment of the lower limbs have been applied widely, and these techniques are currently being used in minimally invasive unicondylar knee arthroplasty (MIS UKA) with good alignment results. To the best of our knowledge, there are no studies showing whether or not MIS UKA using a navigation system has a significant influence on the clinical results. This prospective study investigated the hypothesis that minimally invasive uni-compartmental knee arthroplasty using navigation system (NA-MIS UKA) will produce better short-term clinical results than MIS UKA without navigation system.

After a minimum two-year follow-up, the short-term functional results included the ranges of motion, Hospital for Special Surgery (HSS) scores, and WOMAC scores and the alignment accuracy of the components of 31 NA-MIS UKAs (NA-MIS group) compared with those of 33 MIS UKAs without a navigation system (MIS group). The surgery time was also recorded and compared.

The HSS and WOMAC scores showed significant improvement at the final follow-up in both groups, showing no significant inter-group difference (p=0.071, p=0.096, respectively). The ranges of motion also showed significant improvements in both groups, but there was no significant difference between two groups (p=.687). However, the surgery time was longer in MIS group than in NA-MIS group. NA-MIS UKA produces significant improvement in the desired mechanical axis with prosthetic alignment outliers compared with that without the navigation system.

However, at the final follow-up, there were no significant differences in any of the functional parameters between the two groups.