ROBOTIC-ASSISTED TOTAL KNEE ARTHROPLASTY IS ASSOCIATED WITH EARLIER RETURN OF SYMMETRICAL LIMB FUNCTION COMPARED TO CONVENTIONAL JIG-BASED TECHNIQUES USING WEARABLE SENSORS: A PROSPECTIVE COHORT STUDY

The purpose of this study was to compare outcomes of patients undergoing robotic-assisted total knee arthroplasty (RA-TKA) to conventional jig-based techniques in the early post-operative period using traditional patient-reported outcome measures (PROMs) and wearable sensors. This was a prospective, matched, parallel cohort study of 100 patients with symptomatic end-stage knee osteoarthritis undergoing primary TKA (44 RA-TKA and 56 conventional TKA). Functional outcomes were assessed using ankle-worn inertial measurement units (IMU) and PROMs. IMU-based outcomes included impact load, impact asymmetry, maximum knee flexion angle, and bone stimulus. PROMs, including Oxford Knee Score (OKS), EuroQol-Five Dimension, EuroQol Visual Analogue Scale, and Forgotten Joint Score, were evaluated at pre-operative baseline, weeks 2 to 6 post-operatively, and at 3-month follow-up By post-operative week 6, RA-TKA was associated with significant improvements in maximum knee flexion angle compared to conventional TKA (118o ± 6.6o vs 113o ± 5.4o; p=0.04), symmetrical limb loading (82.3% vs 22.4%; p < 0 .01), cumulative impact load (146.6% vs 37%; p < 0 .01), and bone stimulus (25.1% vs 13.6%; p < 0 .01). Of note, RA-TKA demonstrated an earlier return to symmetrical limb loading, with operative limb IMU-based function reaching 80% of the non-operative limb by post-operative week 3. There were no significant differences in PROMs between the two groups, however, significantly more RA-TKA patients achieved an ‘excellent’ outcome at 6 weeks compared to conventional TKA using OKS subscales (47% vs 41%, p=0.013). RA-TKAs were associated with earlier functional improvements when assessed using IMUs compared to conventional TKA, which were not detected by traditional PROMs during the early post-operative period.