The resorption of bone - A consideration of the underlying processes particularly in pathologic conditions
The resorption of bone - A consideration of the underlying processes particularly in pathologic conditions
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DOI：
10.1001/archsurg.1930.01150090002001
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发表时间：
1930-01-01
影响因子：
--
通讯作者：
Jaffe, HL
中科院分区：
文献类型：
--
作者：
Jaffe, HL
The paper is based upon a study of the literature and a large material seen by the author. In resorption of bone, especially in fulminating and inflammatory disease, all canals in the cortex dilate, with dilatation and increase in number of their contained blood vessels. Haversian canals may coalesce. Enlargement of the canals may be associated with the appearance of Howslip''s lacunae. The Haversian canals become tortuous and lengthened and longitudinal sections of inflamed compact bone may show cross-sections of the canals. In vascular resorption of bone, enlargement of existing vessel canals is more important in reducing bone substance than the formation of Volk-mann''s canals. Because of the intimate anastomoses between the vessels of cortex and medulla, inflammatory changes in the cortex are accompanied by similar changes in the medulla, with resorption of spongy trabeculae, analogous to enlargement of vessel canals of the cortex. There are differences in the character of the vascular changes of resorption in the various inflammatory diseases of bone and in the varying degrees of Ca deficiency in the diet. The amount of dilatation of the vessel canals depends on the degree of vascularization, speed and extent of resorption being less when fewer vessels are present and when granulation tissue is more cellular. Osteoclasts play little part in vascular resorption, and it has not been determined whether the process is preceded or accompanied by decalcification. Enlargement of vessel canals is accompanied by changes in the ground substance of the bone, particularly in the Ca salts. In the region of resorption these appear as large, irregular, coarse granules, whereas in normal bone they are irregular, fine granules. The manner of decalcification and the part played by vessels and granulation tissue are speculative. Decalcification may be brought about by local and general agents, and the extent of decalcification depends upon the cause. Osteoclasts are capable of resorbing bone, but extensive resorption of bone occurs in their absence. Their presence or absence depends upon the cause and the course of resorption, and they are merely an expression of the way in which the tissues are responding to a stimulus. In embryonic life the osteoclast is derived from the mesenchyme, while in later life, both normally and pathologically, it is a reactive cell arising from fusion of resting wandering cells of the tissues supplemented by mononuclears of the circulation. Osteoblasts and bone cells may be present in osteoclasts by virtue of phagocytosis. All osteoclasts observed by the author have acidophilic cytoplasm. Osteoclasts can absorb bone but are of only secondary importance. They finally probably either degenerate locally or enter blood vessels and are removed. They arise locally in Howslip''s lacunae as reactive cells, the stimulus to osteoclast formation varying with the resorptive process. The osteoclasts then remove the decalcified bone. Degeneration of bone cells and enlargement of bone cell lacunae are not important in the actual resorption of bone, but such bone is more subject to resorption.
