一种骨溶解动物模型的评价

目的 通过股骨内置入聚乙烯颗粒及钛钉,建立大鼠假体周围骨溶解模型,为防治假体周围骨溶解提供实验基础.方法 取30只雄性SD大鼠,按随机数字表法分成模型组、假手术组及空白对照组3组.模型组取膝关节直切口,经髌旁内侧入路充分暴露膝关节,经股骨髁间窝钻孔(直径1.5 mm、深度1.5 cm),置入含10 mg/mL聚乙烯颗粒的混合物200 μL,然后置入钛棒(直径1.2 mm、长1.5 cm),骨蜡封闭后逐层缝合.假手术组的前处理同模型组,钻孔后即骨蜡封闭逐层缝合,无颗粒及钛棒置入.空白对照组不做任何处理.常规饲养7周后处死大鼠,取血清及右侧股骨新鲜标本,检测抗酒石酸酸性磷酸酶5b、钙、磷、碱性磷酸酶,血清水平、钼靶摄片、骨组织病理切片及HE染色,观察造模情况.结果 模型组血清Trap-5b水平明显高于其他两组,而碱性磷酸酶水平则明显低于其他两组,差异均有统计学意义(P＜0.05).模型组股骨在钛钉周围有衬性骨溶解征象.组织病理学示:模型组钛棒周围骨小梁稀疏明显,骨小梁排列紊乱,局部断裂缺损,出现明显骨溶解征象.假手术组及空白对照组则为正常影像学及病理学表象.结论 假体周围骨溶解模型具有可行性,可为人工关节无菌性松动提供实验基础.

An animal model of osteolysis

Objective To develop a rat model of bone dissolution for research into prevention and control of osteolysis around a prosthesis.Methods Thirty male SD rats were randomized into an experimental group,a sham operation group and a control group.In the experimental group,the knee joint was exposed via a medial para-patellar incision.A hole of 1.5 nun in diameter and 1.5 cm in length was drilled from the femoral intercondylar notch through the femoral medullary canal.Gelatin gel containing polyethylene particles was injected into the hole at a dose of 200 μL/rat followed by insertion of a titanium rod (1.2 mm in diameter and 1.5 cm in length).The excessive gelatin extruded out of the hole was removed before the hole was covered with bone wax.In the sham operation group,the wound was sutured with nothing inserted after the hole was drilled and covered with bone wax.No measures were taken in the control group.All the rats were euthanized at 7 weeks after surgery to obtain samples of the serum and right femur.The serum levels of Trap-5b(tartrate-resistant acid phosphatase 5b),Ca(calcium),P(Phosphorus) and ALP(alkaline phosphatase) were observed and radiological and histopathological analyses were conducted.Results X-ray showed phenomenon of osteolysis around the titanium rod in the femur in the experimental group.Histopathological observation also showed obvious bone resorption around the rod in the experimental group.The other 2 groups showed normal radiological and histopathological observations.The serum level of Trap5b was significantly higher and the ALP level was significantly lower in the experimental group than in the other 2 groups ( P ＜ 0.05).Conclusion Since the rat model can result in osteolysis around a prosthesis,it can be used for further research on sterile loosening of a joint prosthesis.