Association of testosterone replacement therapy on medical and implant-related complications after total knee arthroplasty: a systematic review and meta-analysis.

BACKGROUND: Testosterone replacement therapy (TRT) is increasingly used for symptomatic hypogonadism. Given its effects on erythropoiesis, inflammatory pathways, and bone metabolism, TRT may influence postoperative outcomes following total knee arthroplasty (TKA), although current evidence remains inconsistent. This study aimed to evaluate the association between TRT and postoperative medical and implant-related complications after TKA. METHODS: PubMed, Embase, and Scopus were searched from inception through January 2026. Studies comparing patients receiving TRT with controls undergoing TKA and reporting postoperative complications were included. Early medical complications (within 3 months) included pulmonary embolism (PE), deep vein thrombosis (DVT), and acute kidney injury (AKI). Implant-related complications (≥12 months) included periprosthetic joint infection (PJI), revision surgery, and periprosthetic fracture (PPF). A random-effects inverse-variance meta-analysis was performed to calculate pooled odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Four retrospective matched cohort studies were included. TRT was not associated with increased risk of PE (OR, 1.2; 95% CI, 0.9-1.6) or DVT (OR, 1.1; 95% CI, 0.8-1.4) within 3 months. However, TRT was associated with higher risk of AKI (OR, 1.3; 95% CI, 1.1-1.6). At longer follow-up, TRT was associated with increased risks of PJI (OR, 1.8; 95% CI, 1.3-2.7), revision surgery (OR, 1.3; 95% CI, 1.2-1.5), and PPF (OR, 2.0; 95% CI, 1.1-3.7). CONCLUSIONS: TRT was not associated with early thromboembolic complications after TKA but was associated with higher risks of AKI and implant-related complications. These findings suggest TRT may represent an associated perioperative risk factor in patients undergoing TKA.