Reduction in complication rate and hospital length of stay following robotic arm-assisted simultaneous bilateral total knee arthroplasty when compared to conventional techniques: a cohort study with minimum one year follow-up

Bilateral simultaneous total knee arthroplasty (TKA) may be indicated in patients with symptomatic bilateral knee arthritis; however, it is associated with higher morbidity and mortality risk compared to staged procedures. We retrospectively reviewed prospectively collected data comparing bilateral simultaneous robotic arm-assisted TKA (RA-TKA) with conventional TKA (CO-TKA), with a minimum 12-month follow-up period. The primary outcomes of interest were 12-month mortality, revision and reoperation rates, as well as inpatient complication rates. Secondary outcomes of interest were surgical duration, hospital length of stay (HLOS), and functional outcomes after 12 months. The functional outcomes were quantified using the Oxford Knee Score (OKS), EQ-5D-5L index, and EQ-VAS. Each outcome was adjusted for relevant patient and surgical factors. A total of 93 patients were identified for inclusion – 50 in the CO-TKA group and 43 in the RA-TKA group. None of the patients in our cohort died within 12 months of undergoing TKR, nor did any require revision surgery during the follow-up period. There was no difference in reoperation rates (hazard ratio = 1.36; p = 0.877); however, there was a significant decrease in the odds of inpatient complications (odds ratio = 0.21, p = 0.023). There was no difference in surgical duration (p = 0.849), but HLOS was shorter in the RA-TKA group by 1.1 days (p = 0.041). Although we found a statistically significant improvement in the OKS by 2.3 points (p = 0.041) in the RA-TKA group, this was not clinically relevant. There was also no difference in EQ-5D-5L index between the two groups (p = 0.335); however, the RA-TKA group demonstrated a clinically and statistically significant increase in EQ-VAS by 10.8 points (p = 0.037). In our patient cohort, bilateral simultaneous RA-TKA was associated with reduced HLOS and lower complication rates, with no substantial differences in other outcomes except for a significant improvement in the EQ-VAS score.