Abstract
Under local anaesthesia bone tissue is removed from the anterior superior iliac spine with a bone cannula. The bone tissue is hydrolysed, and phosphorus and hydroxyproline concentrations are determined in the hydrolysate. The ratio between these concentrations will be independent of the weight, water content, and blood admixture of bone tissue removed. The ratio is determined on 45 normal human beings at the age of 55–75 years. Phosphorus/hydroxyproline ratio is significantly higher in females than in males.