Stea S, Visentin M, Savarino L, Ciapetti G, Donati M E, Moroni A, Caja V, Pizzoferrato A
Laboratory for Biocompatibility Research on Implant Materials, Istituti Ortopedici Rizzoli, Bologna, Italy.
J Biomed Mater Res. 1995 Jun;29(6):695-9. doi: 10.1002/jbm.820290604.
We evaluated bone microhardness at the interface with hydroxyapatite-coated stainless-steel pins used in an external fracture fixation system. Pins were transversally inserted into the diaphyses of sheep tibiae and were loaded in for 6 weeks. Uncoated pins were implanted as controls. Microhardness analysis, based on the measure of the resistance of the bone to the penetration of a small diamond pyramid, yielded an accurate and reproducible measure of the mineralization degree and of the orientation of collagen fibers. Bone tissue close to the pin is less hard than bone tissue far from it. Moreover, the presence of hydroxyapatite coating on the pins did not significantly affect bone hardness; actually, the mean hardness at the interface with the pins was 56.9 Vickers degrees, whereas at the interface with the uncoated pins it was 62.2. It can be concluded that, 6 weeks postsurgery, the bone growing into the threadings of a loaded screwed implant reached maturity at a degree lower than that of the host bone in both uncoated and coated implants.
我们评估了外部骨折固定系统中使用的羟基磷灰石涂层不锈钢针与骨界面处的骨显微硬度。将针横向插入绵羊胫骨骨干，并加载6周。植入未涂层的针作为对照。基于骨对小菱形压头穿透的抵抗力测量的显微硬度分析，得出了矿化程度和胶原纤维取向的准确且可重复的测量结果。靠近针的骨组织比远离针的骨组织硬度小。此外，针上的羟基磷灰石涂层的存在并未显著影响骨硬度；实际上，与针界面处的平均硬度为56.9维氏度，而与未涂层针界面处的平均硬度为62.2。可以得出结论，术后6周，在有负载的螺纹植入物的螺纹中生长的骨，在未涂层和涂层植入物中，其成熟程度均低于宿主骨。
