Does bisphosphonate use in osteoporotic patients undergoing total shoulder arthroplasty have a protective effect? A propensity-matched analysis

Osteoporosis and its associated complications, such as fractures, place a significant burden on health care systems. Bisphosphonates are a standard treatment for osteoporosis, shown to maintain bone mineral density and reduce fracture risk. However, their role in patients undergoing reverse total shoulder arthroplasty (rTSA) remains unclear, particularly regarding complications like acromial stress fractures and other prosthesis-related outcomes. This study investigates the impact of bisphosphonate usage on postoperative outcomes in osteoporotic patients undergoing rTSA. A retrospective cohort study was conducted using the TriNetX Research Network database to identify patients with osteoporosis who underwent rTSA. Patients were stratified into two cohorts based on preoperative bisphosphonate usage. Propensity score matching (1:1) was utilized to balance demographic characteristics, comorbidities, prior surgery, and medication use. Outcomes assessed included acromial stress fractures, revision rates, aseptic loosening, and periprosthetic fractures at 1 year postoperatively. A total of 1,208 propensity-matched patients (604 in each cohort) were analyzed. In the bisphosphonate group, 25 (4.1%) of patients were diagnosed with an acromial stress fracture compared to 23 (3.6%) in the control group (odds ratio 1.142, 95% confidence interval 0.637-2.049, P = .655). No significant differences were observed in revision rates ( P = .712), aseptic loosening ( P = 1.000), or periprosthetic fractures ( P = 1.000) between cohorts. Bisphosphonate usage does not decrease the incidence of acromial stress fractures in osteoporotic patients undergoing rTSA. Future studies should focus on the potential additional interventions to mitigate the risk of acromial stress fracture in osteoporotic patients undergoing rTSA.