Robotic Assisted Versus Manual Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Abstract

Background: Robotic-assisted unicompartmental knee arthroplasty (rUKA) aims to enhance the precision and reproducibility of implant positioning compared with manual UKA (mUKA). This systematic review and meta-analysis compared radiographic, clinical, and patient-reported outcomes between rUKA and mUKA.

Methods: A systematic search was conducted in PubMed, MEDLINE, EMBASE, Scopus and Web of Science (July 2025) for comparative studies of rUKA and mUKA, in line with the PRISMA statement. Data were pooled using random-effects models, with effect sizes expressed as mean difference (MD), standardized mean change (SMC), or odds ratio (OR) with 95% confidence intervals (CIs).

Results: Thirty-four studies encompassing 68,196 UKAs (22,585 robotic; 45,611 manual) were included. rUKA demonstrated significantly lower complication (OR 0.66, 95% CI 0.44-0.99; p = 0.045) and revision rates (OR 0.54, 95% CI 0.39-0.75; p < 0.001). Operative time was longer for rUKA (+16.1 min; 95% CI 10.8-21.4), while length of stay trended shorter (MD -0.2 days; p = 0.44). rUKA was associated with greater functional outcomes, including higher KSS Knee (MD 2.49; p = 0.007), KSS Function (MD 2.33; p = 0.008), and Oxford Knee Score (SMC 1.06; p = 0.049). Radiographically, rUKA yielded lower tibial slope deviation (MD -1.75°; p < 0.001) and reduced variability in tibial slope and hip-knee-ankle alignment.

Conclusion: rUKA may offer benefit compared to mUKA across radiographic precision, complications, revisions, and functional outcomes, though high heterogeneity in study design and the absence of UKA-specific minimal clinically important difference thresholds limits the relevance of any rUKA benefit at present. Further large, multicenter, and methodologically robust studies are needed to confirm long-term results and better define the role of rUKA in clinical practice.