Are peripheral DXA results useful for diagnosing osteoporosis?
Peripheral dual-energy x-ray absorptiometry (pDXA) measures bone mineral density at sites such as the ankle or wrist. It may be useful for predicting short-term risk specifically at the site screened and overall risk of fracture. It should not be used to diagnose osteoporosis or for monitoring treatment. It is not sufficiently accurate to predict the risk of hip fracture, but may point to the need for further screening of the central skeleton (1). Peripheral bone mineral density estimates cannot be used in the FRAX calculation tool (2).
Dual-energy x-ray absorptiometry (DXA) of the spine and/or hip (particularly the total hip or femoral neck) should be obtained in women with a peripheral T score of -1.0 or less to more accurately evaluate fracture risk.
BOTTOM LINE: Peripheral DXA testing does not predict fracture risk at important sites, such as the hip, with sufficient accuracy to substitute for direct measurement at the hip. Peripheral measurements cannot be used to make diagnostic and therapeutic decisions.
- Raisz LG. Screening for Osteoporosis. N Engl J Med 2005; 353: 164-171.
- World Health Organization Fracture Risk Assessment Tool. 0000. Available online.