Robotic vs. conventional total knee arthroplasty over two decades: Evolving trends toward personalised alignment without significant clinical superiority in predominantly mild varus deformity-A systematic review of RCTs.

Purpose: Randomised controlled trials (RCTs) comparing robotic-assisted (RA-TKA) and conventional total knee arthroplasty (C-TKA) have demonstrated evolving trends in alignment strategies, surgical workflows and outcomes measurements. This review synthesises current evidence to clarify the evolving role of RA-TKA over the past two decades. Methods: A PRISMA systematic review was conducted searching PubMed, Cochrane Library, and Google Scholar (2000-2024). Eligible studies were Level I RCTs comparing RA-TKA to C-TKA with well-defined alignment strategies and surgical workflows. Data included demographics, robotic and prosthetic systems, learning curves, outcome measures and complications. Results: From 850 records, 9 RCTs were included (627 TKAs: 317 RA-TKA, 310 C-TKA). Patients averaged 66.9 years, BMI 28.1 kg/m², 27.9% male, 69.7 knees, follow-up 23.7 months. Coronal deformity was predominantly varus (<10°). Robotic systems included Robodoc, Mako, and Navio using cruciate-retaining or posterior-stabilised prostheses. All earlier studies followed mechanical alignment (MA); after 2021 all RA-TKAs adopted personalised alignment strategies. Patellar management varied widely, with no RA-TKA workflow addressing the patellofemoral space. Most procedures were performed by one or two experienced surgeons; learning curves were only noted in early MA studies. RA-TKA reduced alignment outliers by 10%-24% ( Conclusions: Over the past two decades, RA-TKA has evolved substantially, transitioning from purely bone-cutting technology to decision-making platforms enabling alignment personalisation and dynamic soft-tissue assessment, improving surgical precision regardless of alignment strategy. Clinical superiority over C-TKA remains inconclusive in relatively low-risk patients, predominantly older females with varus deformity, highlighting the need for studies with more diverse populations, prosthetic design, long-term follow-up, patient-specific outcomes, standardised workflow and learning curve reporting, and patellofemoral space optimisation. Level of Evidence: Level I, systematic review of non-homogeneous RCTs.