Astrand Jörgen, Aspenberg Per
Department of Orthopedics, Lund University Hospital, Sweden.
Acta Orthop Scand. 2002 Jan;73(1):24-30. doi: 10.1080/000164702317281369.
Bone resorption associated with prosthetic loosening can be reduced by giving bisphosphonates since they bind to bone surfaces and inactivate osteoclasts when bisphosphonate-containing bone is resorbed. During loosening, an increase in osteoclastic activity can be triggered by mechanical instability, fluid pressure or wear particles. We used a rat model in which a titanium surface can be made to slide over a bone surface and cause instability-induced bone resorption. 111 rats were operated on with a plate implant and treated with alendronate or clodronate injections in different doses or saline controls. After 4 weeks of osseointegration, the plate was moved during 2 weeks and the findings evaluated with histomorphometry. The percentage of persisting bone-metal contact and the soft tissue area at the interface were measured to estimate bone loss. Low or intermediate doses of the bisphosphonates increased the ash weight of untraumatized bone, but did not inhibit resorption at the unstable interface. Only rats treated with the highest doses of alendronate or clodronate had more bone-metal contact than controls. Instability-induced bone resorption therefore seems to be reduced by bisphosphonates, but higher doses are needed to obtain this effect than to reduce bone resorption associated with normal remodeling of untraumatized bone.
通过给予双膦酸盐可以减少与假体松动相关的骨吸收，因为它们会结合到骨表面，并在含双膦酸盐的骨被吸收时使破骨细胞失活。在松动过程中，破骨细胞活性的增加可由机械不稳定、流体压力或磨损颗粒引发。我们使用了一种大鼠模型，在该模型中可使钛表面在骨表面滑动并导致不稳定诱导的骨吸收。111只大鼠接受了钢板植入手术，并用不同剂量的阿仑膦酸盐或氯膦酸盐注射治疗或作为生理盐水对照。在骨整合4周后，在2周内移动钢板，并通过组织形态计量学评估结果。测量持续的骨-金属接触百分比和界面处的软组织面积以估计骨丢失。低剂量或中等剂量的双膦酸盐增加了未受创伤骨的灰重，但并未抑制不稳定界面处的吸收。只有用最高剂量阿仑膦酸盐或氯膦酸盐治疗的大鼠比对照组有更多的骨-金属接触。因此，双膦酸盐似乎可以减少不稳定诱导的骨吸收，但与减少未受创伤骨正常重塑相关的骨吸收相比，需要更高的剂量才能获得这种效果。
