Blumer Michael J F, Longato Stefano, Fritsch Helga
Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Innsbruck Medical University, Müllerstrasse 59, Innsbruck, Austria.
Ann Anat. 2008;190(4):305-15. doi: 10.1016/j.aanat.2008.02.004. Epub 2008 May 28.
In the long bones, endochondral bone formation proceeds via the development of a diaphyseal primary ossification centre (POC) and an epiphyseal secondary ossification centre (SOC). The growth plate, the essential structure for longitudinal bone growth, is located between these two sites of ossification. Basically, endochondral bone development depends upon neovascularization, and the early generation of vascularized cartilage canals is an initial event, clearly preceding the formation of the SOC. These canals form a discrete network within the cartilaginous epiphysis giving rise to the formation of the marrow space followed by the establishment of the SOC. These processes require excavation of the provisional cartilaginous matrix which is eventually replaced by permanent bone matrix. In this review, we discuss the formation of the cartilage canals and the importance of their cells in the ossification process. Special attention is paid to the enzymes required in disintegration of the cartilaginous matrix which, in turn, will allow for the invasion of new vessels. Furthermore, we show that the mesenchymal cells of the cartilage canals express bone-relevant proteins and transform into osteocytes. We conclude that the canals are essential for normal epiphyseal bone development, the establishment of the growth plate and ultimately longitudinal growth of the bones.
在长骨中，软骨内成骨通过骨干初级骨化中心（POC）和骨骺次级骨化中心（SOC）的发育进行。生长板是骨骼纵向生长的关键结构，位于这两个骨化部位之间。基本上，软骨内骨发育依赖于新血管形成，血管化软骨管的早期生成是一个初始事件，明显先于SOC的形成。这些管道在软骨骨骺内形成一个离散的网络，导致骨髓腔的形成，随后是SOC的建立。这些过程需要挖掘临时软骨基质，最终由永久性骨基质取代。在本综述中，我们讨论了软骨管的形成及其细胞在骨化过程中的重要性。特别关注软骨基质分解所需的酶，这反过来又将允许新血管的侵入。此外，我们表明软骨管的间充质细胞表达与骨相关的蛋白质并转化为骨细胞。我们得出结论，这些管道对于正常的骨骺骨发育、生长板的建立以及最终骨骼的纵向生长至关重要。
