Comparable clinical outcomes between octogenarians and young patients following robotic-assisted unicompartmental knee arthroplasty.

Abstract

Medial unicompartmental knee arthroplasty (mUKA) may offer significant advantages for octogenarian patients due to its reduced surgical burden. The purpose of this study was to analyze the clinical and radiological outcomes, including complications and implant survivorship, in octogenarians following robotic-assisted mUKA compared to patients aged ≤60 years. We conducted a retrospective analysis of prospectively collected data on robotic-assisted mUKA performed between 2018 and 2022, with a minimum follow-up of 24 months. Inclusion criteria were patients aged ≥80 years and patients aged ≤60 years. Participants without consent were excluded. A total of 203 patients were included in the final analysis. Propensity score matching was performed to balance the two cohorts (Young: ≤60 years; Octogenarians: ≥80 years) based on body mass index (BMI), Oxford Knee Score (OKS) and Knee Society Score (KSS). The Mann-Whitney <i>U</i> test was used to compare continuous variables both preoperatively and postoperatively, as well as clinical improvements across cohorts. The Wilcoxon Signed-Rank Test and the minimally clinically important difference (MCID) were used to evaluate postoperative clinical outcome improvements within each cohort. The <i>Chi-Square</i> test was used to compare survival and complication rates between groups. No differences were found between groups in any clinical or radiographic parameters, either preoperatively or postoperatively. Both groups showed comparable and clinically meaningful improvements in KSS and OKS scores. In the octogenarian group, there were two cases of intracortical lateral tibial fractures managed conservatively. One case of subpopliteal deep vein thrombosis (DVT) occurred in the younger cohort. No differences in implant survival were observed between the groups. Advanced age alone should not preclude octogenarian patients from undergoing robotic-assisted mUKA, as they can achieve meaningful functional improvements comparable to those of younger patients. Level III.