Common Questions
What bone density measurement site correlates best with clinically important fractures?
The hip is the best site for predicting clinically important fractures. A bone density measurement's ability to predict fracture is somewhat site-specific, i.e., wrist densitometry best predicts wrist fracture risk, lumbar spine measurement the spine fracture risk, etc. The upshot is that you might over- or underestimate the risk of hip and spine fractures when relying on peripheral measurements alone. The hip site does best overall.
Note in the following table that hip densitometry not only best predicts hip fracture risk, but it is nearly as good at predicting fractures at other sites (1).
| Measurement Site | Wrist | Hip | Vertebrae |
|---|---|---|---|
| Forearm | 1.8 | 1.6 | 1.6 |
| Femoral neck | 1.6 | 2.6 | 1.9 |
| Lumbar spine | 1.6 | 1.3 | 2.0 |
Because of more rapid loss of bone in the spine in perimenopause, some experts recommend testing the spine as well in this group of women. After age 65, however, spine BMD measurements become much less reliable due to the development of arthritic changes that falsely elevate the density in this area.
- Osteoporosis: Cost-effectiveness analysis and review of the evidence for prevention, diagnosis, and treatment. Osteoporosis International 1998; 8(S4): S7-S86.