微粒导致人工关节假体周围界膜产生TNF-α的实验研究

Experimental studies of TNF-α production in the interface membrane of prostheses after injection of wear debris

目的 :观察人工关节置换中产生的磨损微粒在动物体内引起的反应 ,探讨肿瘤坏死因子 (TNF α)与人工关节松动的关系。 方法 :成年新西兰兔 32只 ,雌雄不限。在兔的股骨远端沿股骨轴线钻孔 ,植入直径 4mm、长 15mm的圆柱形钛合金棒作为模拟假体。按膝关节内注入微粒的不同随机分为四组 ,每组 8只。甲组 :注入超高分子聚乙烯微粒 ;乙组 :注入钛合金微粒 ;丙组 :注入骨水泥微粒 ;丁组 (对照组 ) :注入等渗盐水。术后第 2周开始向关节囊内注入各种微粒悬液 ,每次 0 .2ml,每两周一次 ,直至术后 14周 ,在第 16周处死动物 ,取股骨远端及关节囊。从各组标本中取 0 .2g组织 ,并制成组织匀浆。离心后取上清液 ,放免法测定TNF α含量。 结果 :各实验组组织中的TNF α含量明显高于对照组 (P <0 .0 5 ) ,而各实验组之间无明显差异。 结论 :各种人工关节材料的微粒均能引起相似的反应 ,促进组织中炎性介质TNF α的释放 ,并进一步造成溶骨 ,这是人工关节松动的一个原因。

Objectives:To observe the response to wear debris in animals in vivo and explore the etiopathology of the loosening of prostheses. Methods:A plug of titanium alloy was inserted in the cavity that had been drilled in the distal end of the femur in thirty two adult rabbits.The plug was 15 mm long and 4 mm in diameter. The rabbits were randomly divided into 4 groups. The wear debris of polyethylene were injected into the knee joint in group A, while titanium alloy and bone cement were used instead in group B and group C respectively. The normal saline was injected in group D as control. From the second postoperative week ( P.O.W 2),one bonus of 0.2 ml wear debris was injected into the knee joint every two weeks till P.O.W 14(altogether 7 times).On P.O.W 16,all of the rabbits were killed to obtain the femur and joint capsule. From each sample, 0.2 g tissue were homogenized and centrifuged. After getting the supenatant, the TNF α levels were detected by radioimmunology. Results:The contents of TNF α in group A,B and C were higher than that in group D( P <0.05). Conclusions:Various kinds of wear debris can cause similar responses and promote the release of the inflammatory mediator TNF α.Further they cause osteolysis around prosthesis, which may be one of the reasons of aseptic loosening of prosthesis.