Improved precision and Reduced Technical Errors in Total Knee Arthroplasty Using the Velys Robotic-Assisted Solution: Single-Center Comparative Study

Abstract

Despite advances in total knee arthroplasty (TKA), 7-15% of patients remain dissatisfied with surgical outcomes. Variability in implant positioning and limb alignment are recognized contributors. This study evaluates the surgical precision, coronal alignment, and early clinical safety of an imageless robotic system (VELYSTM Robotic-Assisted Solution) compared to conventional instrumentation. We retrospectively reviewed 342 consecutive TKAs performed between September 2021 and May 2024: 198 with conventional instrumentation and 144 with robotic assistance. Clinical parameters included anterior femoral notching, tibial stem placement, and insert size. Radiographic outcomes included mechanical hip-knee-ankle axis (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), and joint line orientation (JLO). Complication rates within one year were recorded. Femoral notching was significantly reduced in the robotic group (13.9% vs. 25.3%, p = 0.04). Tibial stem extension was less frequently required (15.3% vs. 24.2%, p = 0.01). Average insert thickness was reduced (5.7 ± 0.83 mm vs. 6.04 ± 0.98 mm, p = 0.003). Radiographic analysis of 225 patients demonstrated reduced variability in postoperative alignment with robotic assistance, including fewer alignment outliers and lower incidence of unintended valgus tibial cuts. Complications occurred in 10 manual and 6 robotic cases, with no events attributable to the robotic system. The Velys Robotic-Assisted Solution demonstrated improved surgical precision and radiographic outcomes compared to conventional TKA. Through enhanced intraoperative guidance, surgeon decision-making resulted in reduced femoral notching and stem usage, with more consistent implant positioning. These findings support imageless robotic assistance as a safe and effective enabling technology in TKA.