VELYS robotic-assisted total knee replacement leads to improved mobility, reduction in hospitalisation, surgical duration, and better psychological outcomes: a propensity score matched analysis

Abstract

Background: Robotic TKA (rTKA) was developed to improve implant positioning and accuracy of bone cuts, potentially resulting in improved functional outcomes for the patient. The Depuy Synthes VELYS™ Robotic-Assisted Solution (VRAS) is one of the latest, imageless systems available and utilizes the ATTUNE™ primary knee system. Due to its recency, there is limited literature on the outcomes of VRAS compared to its conventional total knee arthroplasty (cTKA) counterpart. This paper aims to look at the differences between VRAS and cTKA regarding early postoperative and 6-month functional outcomes.

Methods: Registry data of all primary TKAs performed by 3 surgeons from January 2021 to December 2024 from a high-volume arthroplasty center were analysed. Patients who underwent VRAS or cTKA using ATTUNE™ implants were included. Propensity scores were estimated using logistic regression, followed by optimal matching in a 1:1 ratio to establish the VRAS and cTKA groups. Early postoperative outcomes (static/dynamic pain score, ambulation distance, length of stay), 6-month functional outcomes (Knee Society Score, Oxford Knee Score, SF-36, patient expectation/satisfaction scores), and proportion attaining a minimum clinically important difference (MCID) were analysed.

Results: Sixty-five VRAS patients were matched with 65 in the cTKA group. The VRAS showed significantly shorter surgical duration (78.2 vs. 85.5 min, P = 0.04), improved ambulation distance (22.2 vs. 11.3 m, P < 0.001), and shorter length of stay (2.48 vs. 3.66 days, P = 0.01). Both groups showed significant improvements in the majority of the functional outcome scores at 6 months. The VRAS displayed a trend towards higher SF-36 outcome measures, with significant differences in SF-36 vitality (P = 0.001), SF-36 mental component summary (P = 0.015), and a larger proportion of patients achieving SF-36 bodily pain MCID (76.9 vs 60.0%, P = 0.038). More patients reported satisfaction and expectation fulfillment (95.2% vs 92.3% and 92.1% vs 87.7%, respectively), albeit non-significantly (P = 0.718 and P = 0.413).

Conclusion: The VRAS TKA demonstrated superior immediate postoperative advantages and patient-reported functional outcomes at 6 months. Further studies are needed to determine long-term outcomes.

Trial registration: Centralized Institutional Review Board (CIRB: 2024-4046).

Keywords: ATTUNE; Early outcomes; Functional outcomes; Robotic-assisted; TKA; VELYS.

Fig. 1

Image of the VRAS imageless, table-mounted set-up with femoral and tibial arrays in situ

Fig. 2

Image of the oscillating saw being positioned in its precise saw plane

Fig. 3

Bar graph of the percentage of satisfaction and expectations fulfilled at 6 months