Impact of Osteoporosis Medications on Postoperative Complications Following Total Knee Arthroplasty

Bisphosphonates have been the gold standard for osteoporosis treatment in the past decade. However, other medications available on the market are also valuable in the treatment of osteoporosis. Knowledge is limited regarding the incidence of postoperative complications following total knee arthroplasty (TKA) for patients taking these osteoporosis medications. Therefore, our primary objective was to examine the incidence of post-TKA complications in patients taking denosumab, selective estrogen receptor modulators (SERMs), teriparatide, or bisphosphonates at 90 days, 1 year, and 2 years. Our secondary objective was to examine the odds of post-TKA complications in patients taking denosumab, SERMs, or teriparatide, at 90 days, 1 year, and 2 years compared with bisphosphonates. Employing a retrospective cohort design, we used an all-payer national database to identify 28,514 post-TKA osteoporotic patients from 2015 to 2022 taking either bisphosphonates, denosumab, SERMs, or teriparatide. Postoperative complications investigated for each osteoporosis medication included prosthetic joint infection (PJI), surgical site infection, aseptic revision, manipulation under anesthesia, aseptic loosening, venous thromboembolism, and periprosthetic fracture. There was a higher incidence of aseptic revision in post-TKA patients taking denosumab (1.2 vs. 0.6%, 0.7%, 0.9%, <i>p</i> = 0.033) compared with patients taking bisphosphonates, SERMs, or teriparatide, respectively, at 90 days. There was a higher incidence of PJI (0.5 vs. 0.1%, 0%, 0.1%, <i>p</i> = 0.049) and aseptic revision (0.3 vs. 0.01%, 0.1%, 0.1%, <i>p</i> = 0.030) in post-TKA patients taking teriparatide compared with patients taking bisphosphonates, denosumab, or SERM's at 90 days and 1 year, respectively. After multivariate analysis with bisphosphonates set as the control, denosumab showed higher odds of aseptic revision at 90 days (odds ratio [OR] = 2.17, <i>p</i> = 0.007), and teriparatide showed higher odds of PJI at 90 days (OR = 3.46, <i>p</i> = 0.043) and aseptic loosening at 1 year (OR = 5.82, <i>p</i> = 0.026). Teriparatide and denosumab were associated with a higher incidence and odds of certain post-TKA complications compared with bisphosphonates. Our results indicate that bisphosphonates and SERMs are associated with the fewest post-TKA complications, but more studies are needed to appreciate the effectiveness of each medication.