Relations of bone mineral content, ash weight and bone mass: implication for correction of bone mineral content for bone size.

Bone mineral content (BMC) was measured by photon absorptiometry in fresh bone specimens: 35 iliac crest and 39 forearms were used. BMC was related to ash weight, fat-free weight and the amount of bone determined by quantitative histologic methods. Ninety-five per cent of the variation in bone mineral concentration (BMC') in the iliac crest could be explained by variation in ash weight, and 88% of the variation in BMC in the forearm could be explained by variation in the amount of bone determined histologically. The total cross-sectional bone area of radius and ulna could be calculated from the width of the structures measured on the photon absorption curves. Using this parameter and the relation between BMC and ash weight, the actual in-vivo bone mineral content in the forearm could be expressed in terms of ash-weight in grams per cm3 of total bone.