Mean wall thickness of trabecular bone packets in the human iliac crest: changes with age.

The mean wall thickness (MWT) of packets of trabecular bone was measured in undecalcified iliac crest bone samples of 36 normal subjects (14 female and 22 male) under polarized light. The mean wall thickness was 49.7 +/- 8.7 microns at a mean age of 50.9 years. There existed a significant decrease of MWT with advancing age. With an appositional rate of 0.72 micron/day, the mean formation time of iliac trabecular bone packets is 69 days. The decrease of MWT with age corresponds to a decrease in bone formation at the basic multicellular unit (BMU) level with aging and can partly explain the physiological senile osteopenia.