Shirazi-Adl A, Dammak M, Paiement G
Department of Mechanical Engineering, Ecole Polytechnique, Montreal, Quebec, Canada.
J Biomed Mater Res. 1993 Feb;27(2):167-75. doi: 10.1002/jbm.820270205.
An apparatus was developed to measure load-displacement friction properties at the cancellous bone/porous-coated metal plate interface. Bone cubes were obtained from different proximal regions of four resurfaced cadaveric tibiae. Three different porous-surfaced metal plates (one fiber mesh and two bead) and a smooth-surface metal plate were used. In the presence of a constant normal contact pressure (0.10, 0.15, or 0.25 MPa), a variable tangential load up to the maximum resistance of the interface was applied and both relative normal and tangential displacements were recorded. Repetitive and fatigue loadings were also considered. Measured results show that the interface friction curve is highly nonlinear, exhibiting large relative tangential displacements in the range of 50-400 microns before the maximum load is reached. Relative displacements in the normal direction remain below 10 microns. The maximum resistance in friction is independent of the bone excision site, type of porous-surfaced metal plate, magnitude of normal load, placement of bone cubes on metal plates or vice versa, repetition of applied load, and conservation period of bone cubes in saline solution. The smooth-surfaced metal plate has significantly smaller friction resistance than porous-coated ones. The fatigue loading of up to 4000 cycles at 1 Hz, in the presence of 0.25 MPa contact pressure, slightly decreases the interface friction coefficient. Finally, the initial secant stiffness of the interface at 75% of the maximum resistance load is found to be larger for the bone cubes from the lateral and medial regions and for the metal plate with smooth surface.
开发了一种用于测量松质骨/多孔涂层金属板界面处载荷-位移摩擦特性的装置。从四个翻修过的尸体胫骨的不同近端区域获取骨块。使用了三种不同的多孔表面金属板（一种纤维网板和两种珠粒板）以及一种光滑表面金属板。在恒定的法向接触压力（0.10、0.15或0.25兆帕）下，施加可变的切向载荷直至界面的最大阻力，并记录相对法向和切向位移。还考虑了重复和疲劳载荷。测量结果表明，界面摩擦曲线高度非线性，在达到最大载荷之前，在50 - 400微米范围内呈现出较大的相对切向位移。法向相对位移保持在10微米以下。摩擦的最大阻力与骨切除部位、多孔表面金属板的类型、法向载荷大小、骨块在金属板上的放置方式（反之亦然）、施加载荷的重复次数以及骨块在盐溶液中的保存时间无关。光滑表面金属板的摩擦阻力明显小于多孔涂层金属板。在0.25兆帕接触压力下，1赫兹频率下高达4000次循环的疲劳载荷会使界面摩擦系数略有降低。最后，发现来自外侧和内侧区域的骨块以及光滑表面金属板在最大阻力载荷的75%时界面的初始割线刚度较大。
