Summary

Robotic-assisted TKA demonstrated benefits of shorter surgical time, shorter length of stay, fewer MUAs and better early patient-reported outcomes compared with navigated procedures.

Abstract

Introduction

Total Knee Arthroplasty (TKA) is the gold standard treatment for end-stage knee osteoarthritis. The introduction of robotic-assisted TKA (RA-TKA) has been shown to improve accuracy and precision of bone cuts and ligament balancing. However, early reports of the impact of RA-TKA on other intraoperative and post-operative outcomes is conflicting. The aim of this study was to compare intraoperative and post-operative outcomes between RA-TKA and navigated TKA (nav-TKA).

Method

A total of 1,434 consecutive TKA performed at North Shore Hospital between November 2019 and October 2023 were included in this study. Patients were grouped into RA-TKA (n=388) or nav-TKA (n=1,046). Patient characteristics, intraoperative variables, and post-operative outcomes were recorded using clinical notes and radiographic review. Oxford Knee Scores (OKS) were collected via questionnaires at 6 months, 1 year and 2 years after surgery. Differences between categorical data was compared using Fisher’s exact or Chi-squared tests, and differences between continuous variables were compared using t-tests.

Results

Compared to nav-TKA, RA-TKA had a shorter surgical time of around 6 minutes (87 vs. 93 minutes, p<0.001), and RA-TKA patients had a shorter mean length of stay (3.1 vs 3.4 days, <0.001). In a matched cohort, fewer RA-TKA patients underwent subsequent manipulation under anaesthetic (MUA) compared to nav-TKA patients (4% vs. 8%, p=0.04). There were no differences in number of inpatient complications (4% vs. 6%, p=0.31), presentations to ED within 90 days (8% vs. 11%, p=0.32), or revisions (1% vs. 0.5%, p=0.45) between RA-TKA and nav-TKA. At 2-years, RA-TKA patients had higher OKS (41.2±6.7 vs. 39.3±7.7, p<0.01), EQ-5D index (0.88±0.16 vs. 0.82±0.20, p<0.01), EQ-5D Health (80.6±15.5 vs. 77.2±16.9, p=0.04), and lower levels of pain (11.0±18.2 vs. 15.3±20.9, p<0.001).

Discussion

In this cohort of patients, RA-TKA demonstrated benefits of shorter surgical time, shorter length of stay, fewer MUAs and better mid-term patient-reported outcomes compared with nav-TKA procedures.