Variation in bone mineral density between different anatomical sites in a normal local population.

Bone mineral density (BMD) measured using dual energy X-ray absorptiometry (DXA) can be expressed in terms of standard deviations, above or below mean young adult T-scores and above or below age-matched Z-scores. The differences between the left neck of the femur (LN), right neck of the femur (RN) and lumbar spine (L2-L4) were statistically significant, irrespective of whether expressed as T-scores or Z-scores. Therefore skeletal status assessment should involve as many sites as practically possible. Considering the low radiation dose and short scanning time, it is suggested that at least the two femurs and lumbar spine BMD be used in routine osteoporosis risk assessment.