Histomorphology of Metaphysis of Proximal Tibia in Albino Rat

The metaphysis lies at the distal end of the growth plate, between the epiphysis and diaphysis of bone and is the zone of active growth in a long bone. In this review study, the continuity of metaphysis of proximal tibia in albino rat was studied by light microscope following Hematoxylin and Eosin and Masson’s trichrome stains. The metaphysis has been described as having two distinct regions, the primary and secondary spongiosa, containing mainly osteoblasts and osteoclasts amidst abundant blood vessels. The osteoblasts are the bone forming cells whereas the osteoclasts are the chief cells mediating bone resorption. Hence, the metaphysis is the site of active bone remodelling. Before the fusion of diaphysis and epiphyses, the metaphyses are richly supplied with blood through end arteries forming hair pin bends. This is the common site of osteomyelitis in children. The bone cells are the favourite target site of action of drugs, especially the bisphosphonate class of drugs, which are potent inhibitors of excessive osteoclastic mediated bone resorption.