Preoperative risk factors for adverse outcomes following total knee arthroplasty: a systematic review and meta-analysis

Abstract

This systematic review and meta-analysis evaluated preoperative patient factors associated with adverse outcomes after primary total knee arthroplasty (TKA). PubMed and Crossref were searched from 2010 to 2025 according to PRISMA guidance, and the protocol was registered in PROSPERO (CRD420261297849). Eligible studies included adults undergoing primary TKA and reported diabetes mellitus, hypertension, obesity, morbid obesity, or sex in relation to readmission, revision surgery, or deep infection. Random-effects generic inverse variance meta-analyses were performed using odds ratios from adjusted models when available; unadjusted or calculated estimates were used only when adjusted estimates were unavailable. Twelve cohort studies including 1,586,680 patients were included. Diabetes mellitus was associated with higher odds of readmission (OR 1.17, 95% CI 1.05-1.30) and revision surgery (OR 1.17, 95% CI 1.03-1.32). Morbid obesity (BMI ≥40 kg/m²) was associated with readmission, revision surgery, and deep infection. Male sex was associated with readmission and revision surgery, while non-morbid obesity and hypertension were not consistently associated with adverse outcomes. These findings support preoperative risk stratification and optimization for diabetes and morbid obesity before elective TKA. Interpretation should remain cautious because included studies were observational and heterogeneity was substantial in several analyses.