Robot-assisted total knee arthroplasty demonstrates superior radiological but comparable clinical outcomes compared to conventional techniques: A meta-analysis of prospective studies.

Abstract

Purpose: Robot-assisted total knee arthroplasty (RATKA) aims to improve surgical precision and outcomes. This study compared clinical and radiological outcomes between RATKA and conventional total knee arthroplasty (CTKA).

Methods: A systematic review was conducted in accordance with PRISMA guidelines, including prospective studies (Level I/II evidence) from MEDLINE, Embase, Web of Science, and the Cochrane Library, up to 20 May 2025. Clinical outcomes included knee function, pain and quality-of-life scores, assessed at a minimum of one year postoperatively. Complications rates were also collected. Radiological outcomes included assessment of coronal and sagittal limb alignment, joint line restoration, and three-dimensional implant positioning. Risk of bias was assessed using validated tools.

Results: Of 11,916 screened citations, 20 studies (11 RCTs, 9 prospective cohort studies) involving 2421 patients (1268 RATKA; 1153 CTKA) were included, with follow-up ranging from 3 months to 2 years and seven different robotic systems evaluated. Meta-analysis showed that RATKA was associated with improved range of motion (mean difference 5.03°; 95%CI [1.78-8.28]; p = 0.004) and WOMAC scores (total, function and pain). No significant differences were found for OKS, KOOS, FJS or EQ-5D. Complication rates were significantly lower in the RATKA group (11.5%) compared to CTKA (16.7%; OR = 0.62; 95%CI [0.45-0.86]; p = 0.004). Radiographically, RATKA significantly improved coronal alignment, joint line restoration, and sagittal tibial positioning, with fewer outliers, compared to conventional TKA. No significant differences were observed in sagittal femoral alignment, posterior tibial slope, or femoral component rotation. Risk of bias was mostly moderate to low, though concerns remained regarding non-blinded assessments, missing data, and potential industry-related conflicts of interest.

Conclusions: RATKA demonstrated higher precision, reduced radiological outliers and complications compared to CTKA. While clinical scores slightly favoured RATKA, differences were not clinically meaningful. Long-term studies are needed to determine potential benefits in subgroups like severe deformities.

Level of evidence: Level II.