Femoral neck bone mineral density

Method

Areal bone mineral density of the femoral neck region of interest by dual-energy X-ray absorptiometry, in grams per square centimetre. Scanner manufacturer, software version, and region-of-interest placement recorded on the edge; values are not comparable across manufacturers without conversion, and percentage change from baseline is not the same reported quantity as an absolute mean difference.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Confused with lean body mass, because both come off a DXA scanner from overlapping scan protocols. This is a regional areal density of mineralised tissue; lean mass is whole-body fat-free soft tissue. A shared instrument is not a shared endpoint. Also distinct from lumbar spine bone mineral density, a different region of interest that responds faster and more strongly to most interventions and is inflated by degenerative change in older spines — the two sites are reported side by side and must not be pooled. Total hip BMD is a third region again.