Which sites are used to assess BMD for osteoporosis diagnosis per WHO criteria?

• A. Lumbar spine only
• B. Total hip only
• C. Lumbar spine, femoral neck, or total hip
• D. Radius and ulna

Answer: (C)

The essential idea here is that the WHO defines osteoporosis by BMD measurements at sites that best reflect fracture risk and have robust reference data. Specifically, a T-score of -2.5 or lower at the lumbar spine, femoral neck, or total hip, measured by DXA, confirms osteoporosis. These sites are chosen because they are common fracture locations and provide reliable, well-standardized comparisons to young healthy adults. The forearm (radius/ulna) isn’t part of the WHO diagnostic criteria, though forearm BMD can be informative in certain cases or when hip/spine measurements are unreliable.