The Effects of Robotic Assisted TKA: A Retrospective Evaluation of Key Metrics

Abstract

As technology drives improvement in healthcare, the utilization trends for robotics in arthroplasty has continued to increase over the last decade. With the growth of robotics, we must determine if the proposed benefits are worth the increased cost. The purpose of this study was to evaluate inpatient post-operative and post-discharge outcomes of robotic-assisted surgery vs. conventional manual instrumentation, specifically time to discharge, discharge status and opioid consumption post- operatively. Knee Injury and osteoarthritis outcome score (KOOS) was calculated for each group as well.After IRB approval, a retrospective chart review of 100 robotic assisted primary total knee arthroplasty (TKA) and 100 matched controls undergoing conventional TKA was performed. Baseline demographics were recorded as well as post-operative outcomes including length of stay, opioid consumption, discharge status and duration of opioid use. All patients underwent primary TKA from 2016-2018 with minimum 6- month follow-up by a single fellowship trained arthroplasty surgeon at a high-volume joint center. Exclusion criteria included < 6 month f/u, incomplete chart information, inflammatory arthritis, BMI >40.Patients had similar pre-operative demographics including age, BMI, gender, opioid use and baseline depression rates. The robotic assisted TKA group had statistically significant decreased LOS (1.58 vs. 2.18 p< 0.001) and morphine equivalents during their hospital stay (73.52 vs. 102.50 p< 0.02). The robotic group had fewer patients at six weeks requiring opioids (37 vs. 61 p=0.001). Six month post- operative KOOS was 81.73 in the control group and 78.22 in the robotic group, (P>0.05).Robotic-assisted TKA was associated with statistically significant decreased hospital LOS, morphine equivalents, and opioid usage at the 6-week follow up appointment. KOOS for the groups in our study were not statistically different. Although KOOS in the control group trended to be higher, our average KOOS for both cohorts was higher than the national average of 76.8.