Risk of Subsequent Fragility Fractures Observed After Low-Trauma Ankle Fractures

While fragility fractures (FFs) are one of the strongest predictors of subsequent osteoporotic fractures, it remains unclear whether low-trauma ankle fractures have this ability. The aim of the study was to identify the characteristics of patients with low-trauma ankle FFs who develop subsequent FFs. The OPTIMUS initiative is a strategy to improve osteoporosis treatment post-FF in orthopedic clinics. FRAX scores without BMD (FRAX-BMI) were calculated at time of inclusion. Recurrent FFs were recorded over a 48-month follow-up. All FFs were X-ray-confirmed. A total of 265 patients with initial ankle FF were included (190 women; mean age 62.8 ± 9.6 years), of whom 15 developed new FFs. Patients with ankle FFs had longer time until recurrence and lower 2-year incidence of recurrent FFs (3.2%) compared with those having wrist FFs (9.0%) or other initial FFs (9.6%), and 4-year incidence rates of 6.2, 13.4, and 15.3%, respectively (log-rank test, p = 0.001). With an ankle FF at inclusion, recurrent FFs were more frequent in patients with previous FF (6.2 per 100 patient-years; p < 0.01) or high-risk FRAX-BMI scores pre- or post-FF (2.4 or 2.0 per 100 patient-years, respectively; ns), compared to patients without any of these conditions (0.7 per 100 patient-years). Ankle FFs represent a clinical opportunity for identifying at-risk patients who should be targeted for treatment (previous FFs and/or high-risk FRAX). Because of mechanical factors and other contributors involved, ankle FFs themselves do not predict subsequent FFs overall, and their inclusion in FRAX-BMI risk calculation may thus not be warranted.