Risk of Subsequent Fractures in Postmenopausal Women After Initial Fracture

Study Methodology and Population

The authors utilized data from women included in the Women’s Health Initiative study during the years 1993–1998. They conducted a prospective analysis involving 157,282 women aged 50–79 years (average age 63.1 years, average body mass index [BMI] 28.0 kg/m², 83% white, average follow-up duration 15.4 years). Patients treated with bisphosphonates, calcitonin, or raloxifene were not included, and none of the participants were treated with denosumab or parathyroid hormone at study entry.

The primary parameter monitored was the incidence of subsequent fractures of the pelvis, femur, patella, lower leg, ankle or foot (excluding toes), coccyx, vertebrae, forearm or wrist, and upper arm or shoulder during a 10-year follow-up after the initial fracture.

Results

An initial fracture was reported in 47,458 patients (30%). Women with an initial fracture were more likely to be older (p < 0.0001), white (p < 0.0001), had a greater number of falls within 12 months (p < 0.0001), and were less likely to have been on hormone therapy at the study entry (p = 0.001).

The risk of subsequent fractures was increased in all the aforementioned locations regardless of the initial fracture location, even after stratification by ethnicity, BMI, or hormone therapy use. The risk increased across all age groups, including women aged 50–59 years. 

An initial forearm or wrist fracture was associated with a significantly increased risk of subsequent fractures of the upper arm or shoulder, thigh, patella, lower leg or ankle, pelvis, and vertebrae (hazard ratios [HRs] for the individual locations ranged between 2.63 and 5.68).

The risk of hip fracture was increased after an initial forearm or wrist fracture (HR 4.80; 95% confidence interval [CI] 4.29–5.36), upper arm or shoulder (HR 5.06; 95% CI 4.39–5.82), thigh (HR 5.11; 95% CI 3.91–6.67), patella (HR 5.03; 95% CI 4.20–6.03), lower leg or ankle (HR 4.10; 95% CI 3.58–4.68), and vertebrae (HR 6.69; 95% CI 5.95–7.53).

Conclusion

According to the aforementioned analysis, the risk of subsequent fractures increases in postmenopausal women regardless of the location of the initial fracture across all age categories, including women under 60 years old. A new finding is that a patella fracture (previously considered non-osteoporotic) is a prognostic risk factor for subsequent fractures similar to hip or wrist fractures. Therefore, the risk of subsequent fractures should be assessed in every postmenopausal woman with a fracture, and appropriate intervention should be implemented if necessary, including monitoring, lifestyle modifications, and/or the initiation of osteoporosis therapy.

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Source: Crandall C. J., Hunt R. P., LaCroix A. Z. et al. After the initial fracture in postmenopausal women, where do subsequent fractures occur? EClinicalMedicine 2021; 35: 100826, doi: 10.1016/j.eclinm.2021.100826.