Objective: To explore the feasibility of establishment of a artificial joint aseptic loosening mouse model by cobalt-chromium particles stimulation.
Methods: Twenty-four 8-week-old male severe combined immunodeficient (SCID) mice were divided into experimental group ( n=12) and control group ( n=12). The titanium nail was inserted into the tibial medullary cavity of mouse in the two groups to simulate artificial joint prosthesis replacement. And the cobalt-chromium particles were injected into the tibial medullary cavity of mouse in experimental group. The survival of the mouse was observed after operation; the position of the titanium nail and the bone mineral density of proximal femur were observed by X-ray film, CT, and Micro-CT bone scanning; and the degree of dissolution of the bone tissue around the tibia was detected by biomechanical test and histological staining.
Results: Two mice in experimental group died, and the rest of the mice survived until the experiment was completed. Postoperative imaging examination showed that there was no obvious displacement of titanium nails in control group, and there were new callus around the titanium nails. In experimental group, there was obvious osteolysis around the titanium nails. The bone mineral density of the proximal tibia was 91.25%±0.67%, and the maximum shear force at the tibial nail-bone interface was (5.93±0.85) N in experimental group, which were significantly lower than those in control group [102.07%±1.87% and (16.76±3.09) N] ( t=5.462, P=0.041; t=3.760, P=0.046). Histological observation showed that a large number of inflammatory cells could be seen around the titanium nails in experimental group, while there was no inflammatory cells, and obvious bone tissue formation was observed in control group.
Conclusion: The artificial joint aseptic loosening mouse model can be successfully established by cobalt-chromium particles stimulation.
目的: 探讨钴铬颗粒刺激制备小鼠膝关节假体无菌性松动模型的可行性。.
方法: 取 8 周龄雄性 SCID 小鼠 24 只随机分为实验组及对照组（ n=12），于右后肢膝关节胫骨近端髓腔植入钛钉，以模拟人工关节假体置换；其中实验组植入钛钉前于髓腔内注入钴铬颗粒悬液。术后观察小鼠存活情况；术后即刻、2 d 及 5 周时行影像学检查（X 线片、CT 及 Micro-CT 骨扫描），观察钛钉位置及胫骨近端骨密度；5 周时行生物力学测试以及组织学染色，观察胫骨周围骨组织溶解程度。.
结果: 术后实验组 2 只小鼠死亡，其余小鼠均存活至实验完成。术后影像学检查示对照组钛钉无明显移位，钛钉周围有新生骨痂；实验组钛钉周围存在明显骨溶解。术后 5 周实验组小鼠右胫骨近端骨密度值为 91.25%±0.67%、钛钉-骨界面最大剪切力为（5.93±0.85）N，明显低于对照组的 102.07%±1.87%、（16.76±3.09）N，差异均有统计学意义（ t=5.462， P=0.041； t=3.760， P=0.046）。组织学观察示实验组钛钉周围可见大量炎症细胞浸润，对照组无明显炎症细胞且有明显骨组织生成。.
结论: 采用钴铬颗粒刺激能成功制备小鼠膝关节假体无菌性松动模型。.
Keywords: Aseptic loosening; animal model; artificial prosthesis; mouse; osteolysis; wear particles.