Current controversies in bone densitometry.

In the face of increasing use of all types of bone densitometry in the diagnosis and management of osteoporosis, the limitations of the World Health Organization criteria for the diagnosis of osteoporosis based on bone density measurements have become apparent. Controversy has arisen about whether these criteria should be used for the diagnosis of osteoporosis. Using densitometry to monitor changes in bone density as a measure of therapeutic efficacy has been criticized. It has been suggested that changes in bone density are not surrogates for reduction in fracture risk and that regression to the mean invalidates serial testing. There is both truth and fallacy in these controversies. The resolutions are critical to the role of densitometry in clinical practice.