The Effects of Osteoporosis on Ankle and Hindfoot Arthrodesis Outcomes: A Matched Database Analysis

Background Osteoporosis increases fracture risk and impairs bone healing. Ankle, subtalar, and triple arthrodeses are often performed to repair complex osteoporotic ankle fractures. However, in osteoporotic patients, postoperative outcomes following these procedures remain uncharacterized.Purpose To determine the impact of osteoporosis and disorders of bone mineral density (BMD) on outcomes following ankle, subtalar, and triple arthrodesis, and evaluate whether pharmacologic treatment influences outcomes in osteoporotic patients.Study design This was a retrospective cohort study utilizing the TriNetX™ Research Network to identify patients who underwent ankle, subtalar, or triple arthrodesis between January 2010 and September 2024.Methods Patients were stratified into three cohorts: osteoporosis, low BMD, and controls. One-to-one propensity-score matching balanced demographics and comorbidities. Primary outcomes were 90-day hospital utilization and 1-year pseudarthrosis rates. A secondary analysis compared outcomes among osteoporotic patients with pharmacologic treatment versus without.Results Within 90 days of surgery, osteoporotic patients demonstrated higher overall adverse event, hospital readmission, and ED visit rates. At 1 year, the low BMD cohort showed increased incidence of mechanical loosening or displacement, and below-knee amputation when compared to controls, and lower pseudarthrosis rates. No significant differences were observed in 90-day or 1-year outcomes between osteoporotic patients with pharmacologic treatment versus without.Conclusions Osteoporosis and low BMD are associated with increased morbidity following ankle, subtalar, and triple arthrodesis, particularly postoperative complications and mechanical failure. Osteoporotic patients demonstrated higher rates of adverse events, hospital readmission, and ED visits. This underscores the need for standardized preoperative bone health screening and targeted preoperative optimization strategies.