Incidence of Total Knee Arthroplasty in Older Females with Knee Osteoarthritis and Osteoporosis Treated with Denosumab Compared with Those Treated Using Bisphosphonates: A Population-Based Cohort Study

This study aimed to evaluate the incidence of total knee arthroplasty (TKA), a marker of severe knee osteoarthritis (OA), among older females with concurrent knee OA and osteoporosis (OP) who were treated with denosumab or bisphosphonates. By analyzing a large population-based cohort, we sought to clarify how these treatments influence the progression of knee OA to the point of requiring surgical intervention. We used data from the Taiwan National Health Insurance Research Database, including data from females aged ≥ 50 years diagnosed with knee OA and OP who initiated treatment between 2012 and 2019. Propensity score matching (1:1) resulted in the selection of 13,774 patients (6897 per group). The TKA incidence was analyzed using Cox proportional hazards models. Patients treated with denosumab had a lower TKA incidence than those treated with bisphosphonates (6.9 vs. 8.5 per 1000 person-years). The adjusted hazard ratio (aHR) for TKA in the denosumab group was 0.77 (95% CI: 0.62-0.97; <i>p</i> = 0.024), with the most pronounced effect observed in patients aged ≥ 80 years (aHR = 0.39, 95% CI: 0.20-0.77; <i>p</i> = 0.007). These findings suggest that denosumab reduces TKA risk more effectively than bisphosphonates and may serve as a superior treatment option for mitigating severe knee OA progression, especially in older adults.