Van der Vis H M, Aspenberg P, Marti R K, Tigchelaar W, Van Noorden C J
Department of Orthopaedic Surgery, Academical Medical Centre, Amsterdam, The Netherlands.
Clin Orthop Relat Res. 1998 May(350):201-8.
High fluid pressures can be present throughout the effective joint space after total hip replacement and can extend locally to the bone implant interface. A new experimental implant model was developed to study whether local fluid pressure can induce osteolysis at a bone implant interface. Twelve mature rabbits received a titanium implant that was allowed to osseointegrate before a fluid pressure of 150 mm Hg was applied to a specific area of the titanium bone interface in six of the animals. Osteolysis occurred in all six implants exposed to the fluid pressure. In two of these animals, no measurable flow occurred. In both animals a localized osteolytic lesion developed with evidence of osteocyte death in the surrounding cortical bone. In four animals, fluid flow away from the lesion occurred after several days that corresponded to either the formation of a canal through the cortical bone or extended resorption of the surrounding cortical bone. In some of these specimens, the microscopic appearance was similar to that of prosthetic loosening: high numbers of macrophages were observed containing intracellular bone particles. No resorption was found in any of the six control animals. The authors' results point to the possibility that all features of prosthetic loosening that are ascribed to particle activation can be explained alternatively by effects of fluid pressure.
全髋关节置换术后，在整个有效关节间隙内可能存在高流体压力，且可局部延伸至骨植入物界面。开发了一种新的实验性植入模型，以研究局部流体压力是否会在骨植入物界面引发骨溶解。12只成年兔子接受了钛植入物，在其中6只动物的钛骨界面特定区域施加150毫米汞柱的流体压力之前，先让植入物进行骨整合。在所有6个暴露于流体压力的植入物中均出现了骨溶解。在其中2只动物中，未检测到流体流动。在这两只动物中，均出现了局部溶骨病变，周围皮质骨中有骨细胞死亡的迹象。在4只动物中，几天后出现了远离病变的流体流动，这与通过皮质骨形成通道或周围皮质骨的广泛吸收相对应。在其中一些标本中，微观外观与假体松动相似：观察到大量含有细胞内骨颗粒的巨噬细胞。在6只对照动物中均未发现吸收现象。作者的结果表明，所有归因于颗粒激活的假体松动特征，都有可能通过流体压力的作用得到另一种解释。
