Analisi morfometrica computerizzata delle variazioni strutturali della diafisi di ossa lunghe umane in rapporto all'età.

The authors studied the micro - structural changes of aging long bones. The results show: an increase in the number of the osteons; a sensible decrease in their sectional area; a disappearance of the outer fundamental system until the sixth decade, which undergoes no significant changes afterwards. Whereas the area of the haversian canals and the percentage of the haversian system undergo no significant changes. The data suggest that the skeletal remodeling tends to keep constant, during the lfetime, the quota of the haversian system and the relation between the latter and the interstital system, through an increase in numebr of the osteons which involves a decrease in their size. On the other hand, this involvs an increase in the number of the haversian canals which brings about the appearence of the well - known phenomenum of the physiological osteoporosis which determines a deterioration of the biomechanic properties of bone.