After the initial fracture in postmenopausal women, where do subsequent fractures occur?

Background: The locations of subsequent fractures after initial fracture in postmenopausal women are poorly characterized. Methods: We conducted a prospective analysis of subsequent fractures after initial fracture in Women's Health Initiative (1993–2018) participants who provided follow-up (mean 15.4 years, SD 6.2 years) data (n = 157,282 participants; baseline age 50–79; 47,458 participants with incident fracture). Cox proportional hazards models were adjusted for age, race/ethnicity, body mass index, and other covariates. Findings: The risk of each type of subsequent fracture was increased after each type of initial fracture. Incident lower arm/wrist fracture was associated with significantly elevated risks of subsequent fractures at the upper arm/shoulder, upper leg, knee, lower leg/ankle, hip/pelvis, and spine (adjusted hazard ratios [aHRs] ranging 2·63–5·68). The risk of hip fracture was increased after initial lower arm or wrist fracture (aHR 4·80, 95% CI 4·29–5·36), initial upper arm or shoulder fracture (aHR 5·06, 95% CI 4·39–5·82), initial upper leg fracture (aHR 5·11, 95% CI 3·91–6·67), initial knee fracture (aHR 5·03, 95% CI 4·20–6·03), initial lower leg/ankle fracture (aHR 4·10, 95% CI 3·58–4·68), and initial spine fracture (aHR 6·69, 95% CI 5·95–7·53). Associations were significant in all age groups, even women aged 50–59 years. Risks of subsequent fracture were more pronounced among non-Hispanic Black, Hispanic/Latina, and Asian/Pacific Islander than among non-Hispanic White women. Interpretation: Increased risk of subsequent fracture is observed for all fracture types across all ages. Women who experience any of these fractures should be targeted for interventions to prevent subsequent fractures. Funding: National Institutes of Health HHSN268201600018C,HHSN268201600001C, HHSN268201600002C, HHSN268201600003C, and HHSN268201600004C.