CONTEXT: Noninvasive measurement of bone marrow adipose tissue using magnetic resonance imaging and proton density fat fraction (PDFF) may enhance clinical fractures prediction in postmenopausal women. OBJECTIVE: This study aimed to assess the association between PDFF measurements and clinical fracture incidence. METHODS: A longitudinal study was conducted. Postmenopausal women with recent osteoporotic fractures (<
12 months) and with osteoarthritis without fractures were included. Lumbar spine and proximal femur PDFFs were measured at baseline using water-fat imaging (WFI) and dual-energy x-ray absorptiometry scans. Clinical fractures were recorded during follow-up. RESULTS: Among 195 participants (mean age 67.4 ± 10.0 years, body mass index 27.2 ± 5.9 kg/m²), the PDFF (WFI-based) was higher at the proximal femur, particularly at the femoral head (90.0% ± 4.9%), compared to the lumbar spine (57.8% ± 9.6%). Over a mean follow-up period of 37.2 ± 11.6 months, 7 participants died, 29 (14.9%) experienced incident clinical fractures, and 1 was lost to follow-up. The lack of an association between WFI-based PDFFs and the incidence of clinical fractures was demonstrated regardless of the region of measurement (hazard ratio [HR] = 0.95 [95% CI 0.67-1.35], CONCLUSION: This study found no evidence of a relationship between PDFF and clinical fracture incidence in postmenopausal women. Further studies are necessary involving larger cohorts and longer follow-up periods.