Prescription Testosterone Increases the Risk of Reoperation for Infection and All-Cause Reoperation after Primary Total Knee Arthroplasty

The rate of total knee arthroplasty (TKA) continues to rise, and with it, the need to identify risk factors for reoperation. Additionally, supplemental testosterone use in male patients has increased across the United States. As more patients taking prescription testosterone replacement therapy (TRT) undergo TKA, there is a need to evaluate TRT as it relates to outcomes following TKA. This study aims to evaluate whether the prescription of supplemental testosterone is a risk factor for reoperation and reoperation for infection following TKA. A retrospective cohort study using a nationwide commercial claims database was conducted. About 76,276 male patients who underwent TKA were identified with a 1.9-year mean follow-up. Reoperations and reoperations for infections were identified using the International Classification of Diseases Tenth Edition (ICD-10) and the Current Procedural Terminology (CPT) codes. Patients were matched based on demographic, geographic, and comorbidities data using Mahalanobis nearest neighbor matching. Statistical analysis was conducted on 3,209 male patients prescribed testosterone and 32,090 not prescribed testosterone. Demographic and comorbidities, including age, location of TKA, length of stay, history of diabetes mellitus, hypertension, hyperlipidemia, obesity, smoking, alcohol, and Charlson Comorbidity Index (CCI) score, were similar (<i>p</i> > 0.05) between male patients prescribed testosterone and men who were not. Men prescribed testosterone had a significantly higher cumulative incidence of reoperation for infection than patients not prescribed testosterone at 1 (<i>p</i> = 0.01), 2 (<i>p</i> < 0.001), 3 (<i>p</i> < 0.001), 4 (<i>p</i> < 0.001), and 5 years postoperatively (<i>p</i> < 0.001). Men prescribed testosterone had a significantly higher cumulative incidence for all-cause reoperation than patients not prescribed testosterone at 1 (<i>p</i> = 0.01), 2 (<i>p</i> = 0.003), 3 (<i>p</i> = 0.01), 4 (<i>p</i> < 0.001), and 5 years postoperatively (<i>p</i> < 0.001). Male patients who were prescribed supplemental testosterone within 1 year prior to primary TKA were at an increased risk for both all-cause reoperation and reoperation due to infection. Surgeons should consider the risks and benefits of testosterone cessation in the perioperative period for patients undergoing TKA.