DOES ROBOTIC ASSISTANCE IMPROVE EARLY FUNCTIONAL OUTCOMES FOLLOWING UNICOMPARTMENTAL KNEE ARTHROPLASTY?

Robotic assistance is purported to confer benefit in unicompartmental knee arthroplasty (UKA) due to an assumed correlation between higher surgical precision and superior outcomes. Our aim was to compare early patient-reported outcome measures (PROMs) between robotic-assisted and manual UKA in our high-volume arthroplasty centre. This was a retrospective cohort study comparing robotic-assisted and manual fixed-bearing cemented medial UKA performed between April 2021 and March 2024. PROMS were assessed at six weeks and one year post-operatively using the Oxford Knee Score (OKS), Forgotten Joint Score (FJS) and satisfaction on a 4-point Likert scale. 395 robotic and 170 manual procedures were performed. Groups were comparable for age, gender, and BMI. PROMs at six weeks were similar, with mean OKS 31.4 in robotic and 33.6 in manual UKA ( p = 0.02) and mean FJS 35.1 and 42.6 respectively ( p = 0.01). Although statistically significant, these differences were lower than the reported minimal clinically important differences (MCID). At one year the mean OKS were 38.7 for robotic and 41.8 for manual UKA ( p =0.01), with FJS 57.8 and 73.2 respectively ( p <0.01), the FJS difference exceeding MCID. Satisfaction for robotic vs. manual was 87.2% vs. 90.6% at six weeks and 87.1% vs. 90% at one year. In conclusion manual UKA showed only a small advantage in FJS at one year, which may reflect a subtly higher performing implant. Differing implants and the retrospective, non-randomised nature of this study may limit generalisability of these findings. Longer-term followup may be advantageous to see if this difference is maintained.