Changes in Density of the Human Femoral Cortex with Age

It is generally believed that osteoporosis is a condition in which there is insufficient bone matrix produced but the mineral content is normal. Osteoporosis occurs in senility, at the menopause and in other conditions of hormonal imbalance. It may also be associated with muscular paresis, prolonged immobilisation and perhaps in conditions of calcium imbalance. Despite considerable information on the occurrence of osteoporosis in well defined clinical conditions, little is known about the changes in bone density that might be expected in the ageing subject. Ingalls(193 1) showed that, ingeneral, the weight ofvarious human bones decreased with age. Trotter, Broman and Peterson (1960) measured the total volume of a number of intact bones from whole skeletons and found a gradual decrease with age in the weight/volume ratio of various bones. In the present work the density of cortical bone, its width and its degree of mineralisation have been determined in specimens of human femora taken at necropsy from ninety-one subjects whose ages and medical history were known.