Osteoporosis predicts high-trauma as well as low-trauma fractures.
It is generally believed that osteoporosis increases the risk for fractures from low trauma (falls from a standing height or less) but not from high trauma (motor vehicle accidents and falls from greater than standing height). In two national prospective cohort studies assessing this issue, approximately 8000 women were followed for 9 years, and 6000 men were followed for 5 years (mean age, about 74 in both cohorts).
A total of 264 women and 94 men reported first-incident high-trauma fractures, and 3211 women and 346 men reported first-incident low-trauma fractures. In analyses adjusted for age, body-mass index, exercise, prior fractures, chronic medical conditions, and treatment for osteoporosis, a 1-standard deviation decrease in bone-mineral density (BMD) at the femoral neck was associated with an increase in risk for high-trauma fractures of 23% in women and 41% in men and an increase in risk for low-trauma fractures of 46% in women and 66% in men. Results were similar for lumbar spine and total hip BMD. Women who sustained high-trauma or low-trauma fractures had similarly increased risks for subsequent fractures compared with women who did not sustain fractures.
Comment: Because osteoporosis predicts an increased risk not only for low-trauma but also high-trauma fractures, it should be considered clinically important in both settings. In addition, clinical trials should include high-trauma fracture as a medical and economic consequence of osteoporosis.
Published in Journal Watch General Medicine December 4, 2007
Mackey DC et al. High-trauma fractures and low bone mineral density in older women and men. JAMA 2007 Nov 28; 298:2381.