Orthopaedic Clinic Lucerne, Hirslanden Clinic St. Anna, St. Annastreet 32, 6006, Lucerne, Switzerland.
Semin Immunopathol. 2011 May;33(3):245-56. doi: 10.1007/s00281-011-0241-4. Epub 2011 Jan 21.
The different properties of bone must be considered in order to understand the relation between orthopaedic devices and bone. The epi-/metaphyseal areas are defined by their rigidity, their high vascularity and their quick remodelling process. In contrast, the diaphyses of bone are rather elastic and built of dense, scarcely vascularised bone presenting slow remodelling. Implants can integrate by pure mechanical contact without real affinity to bone or, alternatively, they can favour ongrowth of bone, provided that they are osteoconductive. Amongst different bone substitutes, only some of them are absorbable. Only derivates of bone may present the property of osteoinduction, which is the power to create new bone in any region of the body. Orthopaedic devices are characterised by their shape, their stiffness or elasticity and by the characteristic properties of material. They may be osteoconductive such as titanium alloys and some ceramics, allowing integration in bone. Alternatively, other materials such as steel, CoCr alloys and PMMA cements remain separated from bone by a tiny layer of collagen. The surface structure influences the quality of integration. The integration of implants depends on the mutual interaction of the material with the tissue on the implantation site. All implants undergo fatiguing which can lead to fracture of the implant. All implant-bone contacts are threatened by granulation tissue mainly formed because of wear products, infection and other reasons.
为了理解矫形装置与骨之间的关系，必须考虑骨的不同特性。骺-/骨干区域的特征为其刚性、高血管化和快速重塑过程。相比之下，骨的骨干部分则具有弹性，由致密、血管化程度低、重塑速度慢的骨构成。植入物可以通过纯机械接触进行整合，而无需与骨骼真正亲和，或者它们可以促进骨骼的生长，前提是它们具有骨诱导性。在不同的骨替代物中，只有其中一些是可吸收的。只有骨的衍生物可能具有成骨诱导性，即能够在身体的任何部位产生新骨的能力。矫形装置的特点是其形状、刚度或弹性以及材料的特性。它们可以是骨诱导性的，如钛合金和一些陶瓷，允许与骨整合。或者，其他材料，如钢、CoCr 合金和 PMMA 骨水泥，通过一层薄薄的胶原蛋白与骨骼分离。表面结构会影响整合的质量。植入物的整合取决于材料与植入部位组织的相互作用。所有植入物都会发生疲劳，这可能导致植入物断裂。所有植入物-骨的接触都受到肉芽组织的威胁，肉芽组织主要是由于磨损产物、感染和其他原因形成的。
