In the normal adult, bone resorption and formation are finely balanced, so that the amount of bone formed in the BSU is equivalent to the amount resorbed. Thus, overall size and form remain constant. Based on this premise, we define basic metabolic bone alterations in terms of the replacement of old bone by new bone in BRU.
Here, we show a normal bone in terms of quantity and morphology. Under these normal conditions, trabecular bone tissue constitutes 16-23 % of total bone tissue (trabecular bone + bone marrow).
Strictly speaking, Osteoporosis and Osteosclerosis only reflect quantitative bone changes, without implying alteration of the internal structure.