China
Africa
Explore chapters and articles related to this topic
In Vivo Bone Imaging with Micro-Computed Tomography
Published in de Azevedo-Marques Paulo Mazzoncini, Mencattini Arianna, Salmeri Marcello, Rangayyan Rangaraj M., Medical Image Analysis and Informatics: Computer-Aided Diagnosis and Therapy, 2018
Steven K. Boyd, Pierre-Yves Lagacé
The basic structural element of cortical bone is the osteon, a cylindrical structure (~250 µm diameter) that is composed of concentric bony lamellae, with a hollow canal (Haversian canal) in its center through which pass capillaries and nervous fibers (Martin and Burr 1989). They are connected by Volkmann’s canals, which run perpendicularly to osteons and allow for fluid flow and nutrient transport. Trabecular bone is organized much differently than cortical bone at the macroscopic level. It is much less densely packed and is composed of a network of interconnecting plates and rods called trabeculae (Martin and Burr 1989). Trabeculae range in size from 75 to 200 µm. As for osteons, trabeculae are composed of lamellae, which are, however, organized longitudinally (Kragstrup et al. 1983). Both bone compartments contribute to the mechanical properties of whole bones, and alterations to either of them will impact the ability of a bone to fulfill its functions, mechanical and physiological.
An Overview of Human Bone, Biomaterials and Implant Manufacturing
Published in Pankaj Agarwal, Lokesh Bajpai, Chandra Pal Singh, Kapil Gupta, J. Paulo Davim, Manufacturing and Industrial Engineering, 2021
Pradeep Singh, Pankaj Agarwal, I.B. Singh, D.P. Mondal
The hierarchical structure of a bone is shown in Figure 9.1(a) (Sadat-Shojai et al. 2013). As observed in this figure, the outermost layer of the bone is the combination of vascular tissues that covers the bone and is known as the periosteum. After the periosteum, the compact and dense part of the bone is known as compact or cortical bone, and the inner part that is highly porous (porosity 70%–90%) and spongy in nature is known as cancellous bone. Cancellous bone has an interconnected 3-D network of the pores in which tissues grow and the transportation of body fluids takes place. A highly porous structure houses the bone marrow, blood vessels and other organic nutrients. The formation of red blood cells, certain white blood cells and platelets (hematopoiesis) also happen in the soft core of the bone marrow (White, Black, and Folkens 2011). Cortical bone has a very dense structure (with a porosity of 5%–40%) and acts as a protective wall for the inner cancellous bone. It facilitates the transportation of body fluid through Haversian and Volkmann’s canal. Haversian canals are the series of micro-tubes surrounded by the concentric lamellae jointly known as osteons (Rho, Kuhn-Spearing, and Zioupos 1998). In the macroscopic view, it can be visualised that the diameter of the osteon is approximately 200 μm. Volkmann’s canals are the tiny interconnected channels that transport the blood, and these are interconnected to the Haversian canals. At the micro-level, bones are made of plate-shaped lamellae which are a combination of cylindrical collagen fibres. Collagen is a type of insoluble protein which is abundantly found in the animal kingdom. The molecules of collagen are packed together in the form of plate-shaped hydroxyapatite crystals. These crystals are assembled in layers that form thin, cylindrical fibrils. Collagen fibres are the conjoint form of these cylindrical fibrils.
Usage of Additive Manufacturing in Customised Bone Tissue-Engineering Scaffold
Published in Harish Kumar Banga, Rajesh Kumar, Parveen Kalra, Rajendra M. Belokar, Additive Manufacturing with Medical Applications, 2023
Volkmann canals are similar canals albeit of a smaller diameter present at 90° angles to the Haversian system which connects them to their neighbours. Being concentric in arrangement, the Haversian canals do not relate geometrically to each other. The interstitial lamella is the region of mature bone organised as lamellae which join the concentric arrangement of the mature bone organised as Haversian systems.
The opportunity of using alloplastic bone augmentation materials in the maxillofacial region– Literature review
Published in Particulate Science and Technology, 2019
Simion Bran, Grigore Baciut, Mihaela Baciut, Ileana Mitre, Florin Onisor, Mihaela Hedesiu, Avram Manea
Compact bone can be found under the periosteum and in the diaphyses of long bones. It provides support and protection, surrounding a central (medullar) cavity which is filled with spongy bone (Granke 2015). The compact bone is composed of structural units called osteons, or Haversian systems. Osteons are composed of concentric rings of calcified matrix called lamellae, surrounding a central canal, or Haversian canal, containing nerves, blood vessels and lymphatic vessels. These central canals communicate with each other through perforating canals, also known as Volkmann’s canals. Osteocytes are located inside spaces called lacunae, found at the borders of adjacent lamellae. Spongy bone has a higher metabolic activity compared to any other bone compartments (Gropp 2017).