Beta Blocker Use and Total Knee Arthroplasty Among United States Medicare Beneficiaries

BACKGROUND/OBJECTIVES: Preclinical evidence suggests beta blockers may reduce cartilage degradation and delay knee osteoarthritis (OA) progression. While beta blockers are widely used in patients with hypertension, their potential role in preventing total knee arthroplasty (TKA) is unclear. Therefore, we assessed the association between beta blocker use and TKA in knee OA patients with hypertension. METHODS: We conducted a nested case-control study using a nationally representative sample of Medicare beneficiaries with newly diagnosed knee OA and prevalent hypertension from 2011 to 2020. Beneficiaries who underwent TKA were defined as cases, while those without TKA were defined as controls. Cases and controls were matched at a 1:4 ratio based on pre-specified criteria using incident density sampling. We measured binary (exposed/unexposed) and cumulative exposure of beta blockers during 6 months before TKA using total standardized daily doses (TSDD) for each patient, categorized as unexposed (0), < 1-200, 201-400, 401-600, 601-900, > 900. Confounding was addressed using propensity score adjustment and stratification for the binary exposure and direct covariate adjustment for cumulative exposure in conditional logistic regression models. RESULTS: We included 30 338 beneficiaries with TKA and 106 145 matched controls. The mean age (SD) was 74.4 (5.5) years, and 67.1% were women in both groups. There was no significant association between beta blocker use and odds of TKA (adjusted OR [aOR] 1.01; 95% CI, 0.97-1.02) compared with unexposed individuals. Smilarly, no cumulative exposure category was associated with TKA risk (TSDD: < 1-200 [aOR, 1.01; 95% CI,0.97-1.04]; TSDD: 201-400 [aOR 1.00; 95% CI, 0.96-1.05]; TSDD: 401-600 [aOR, 1.02; 95% CI, 0.96-1.08]; TSDD: 601-900 [aOR 0.94; 95% CI, 0.87-1.00]; and, TSDD: > 900 [aOR 0.99; 95% CI, 0.91-1.08]), compared with the unexposed group. CONCLUSION: We found no evidence to support that beta blocker exposure reduces the likelihood of TKA.