骨水泥阻塞髓腔后骨内压升高对远侧关节影响的实验研究

Experimental study of the effect on the the distal femoral joint by the high intraosseous pressure induced with blocking of the proximal and middle femoral medullary cavity with bone cement

[目的]探讨骨水泥阻塞股骨近中段骨干髓腔后骨内压升高对远侧关节组织结构的影响。[方法]将26只实验兔分成4组,随机取出8只不做模型而作为正常对照组,其余18只采取左侧股骨髓腔内灌注聚甲基丙烯酸甲酯(PMMA)骨水泥而右侧不灌注,制作骨水泥阻塞股骨近中段骨干髓腔的动物模型,根据不同观察时间段随机分成术后4(T4)、8(T8)和16周(T16)3个观察组。对正常对照和模型动物实验侧股骨远端软骨、软骨下骨和滑膜组织标本,采用HE染色、甲苯胺蓝染色、免疫组织化学检测及透射电镜方法进行组织结构观察。[结果](1)HE染色:关节软骨、软骨下骨和关节滑膜组织损害随时间呈进行性加重,造模16周关节软骨破坏,骨组织结构损害,滑膜组织增生、肿胀。(2)甲苯胺蓝染色:造模16周关节软骨全层失染。(3)免疫组化:①Ⅱ型胶原:造模16周软骨细胞染色阳性。②TGF-β1:造模16周软骨细胞染色阳性,关节滑膜细胞染色阳性。(4)透射电镜:关节软骨和骨细胞损害随时间呈进行性加重,造模16周部分软骨细胞和骨细胞坏死、崩解。[结论]骨水泥阻塞股骨近中段骨干髓腔后导致股骨远端血循环障碍,骨内压升高,持续骨内高压加重了股骨远端的缺血缺氧状态,使股骨远端骨代谢发生紊乱,最终造成股骨远端骨、软骨和滑膜组织发生了退变或坏死。

[ Objective ] To explore the effects on the distal femoral joint by high intraosseous pressure after blocking of proximal and middle femoral medullary cavity with bone cement. [ Method ] The rabbit model was established whose proximal and middle femoral medullary cavity of left side was infused with PMMA while the right side served as the control. Twenty-six rabbits were cavided randomly into 4 groups, 8 for normal control group, the remained modeled rabbits were grouped according to the observing time-point into following groups ： 4th （ T4 ） , 8th （ Ts ） and 16th week （ T16 ）. The rabbits was killed to obtain the samples of distal femoral articular synovium, cartilage and the bone under cartilage. Then the structural changes of these tissues were observed by HE staining, toluidine blue staining, immunohistochemistry and transmission electron microscope. [ Result] （ 1 ） HE staining： the damage to articular cartilage, synovial tissue and the bone under cartilage aggravated with time. At the 16th week, it showed the articular cartilage was destructed, the bone structure was severely damaged with the synovial tissue proliferation and swelling. （2） Toluidine blue staining （16th week） ： all the layers of articular cartilage appeared loss of stain while the superficial layers were slightly loss of stain in control group. （3） Immunohistochemistry （16th week） ： ①Collagen lI ： the chondrocytes were positively stainned. ②TGF-β1： chondrocytes stain was positive ; the staining of articular synoviocytes appeared positive. （4） Transmission electron microscope： The lesions to articular chondrocytes and bone cells aggravated with time, part of which presented with necrosis and collapse at the 16th week. [ Conclusion ] The distal femoral intraosseous and intramedullary blood circulation is severely damaged after blocking of the proximal and middle femoral medullary cavity with bone cement, leading to continuous high intraosseous pressure. It makes the bone metabolism disordered in distal femur, which results degeneration and necrosis in distal femur, cartilage and synovial tissue.