兔膝骨关节炎进程中软骨下骨血管生成的实验研究

目的 探讨兔膝骨关节炎发展进程中软骨下骨血管生成的时间依从性的变化,研究软骨下骨血管新生在OA发病机制中的作用.方法 30只新西兰大白兔随机分为前交叉韧带切除组（ACLT组）、对照组,每组15只.ACLT组右膝前交叉韧带切除造模,对照组不作任何处理.分别于术后4周、8周、12周取材.取兔膝关节标本进行大体观察,切片行组织学番红O染色及OARSI病理评分,评价软骨退变.行免疫组化VEGF染色,观察软骨下骨中血管生成情况,同时用Image Pro Plus 6.0图像分析软件进行骨软骨交界血管数量密度的计数检测.结果 ACLT组术后4周即可见软骨退变,8周和12周时退变进一步加重,番红O染色基质丢失、软骨变薄及裂隙生成、软骨下骨裸露.对照组无明显软骨退变,不同组关节软骨OARSI评分有统计学差异（F=440.828,P〈0.01）.切片免疫组化血管内皮生长因子（VEGF）染色示ACLT组阳性表达,ACLT组的血管入侵软骨数目明显高于对照组,且OA各时间点之间有统计学差异（F=72.733,P〈0.01）.结论软骨下骨的血管生成是OA的早期病变,OA中骨-软骨复合单元的血管增生与软骨退变相关.血管侵入软骨的数量密度与OA发展呈时间依从性增加变化.

Angiogenic activity of subchondrai bone during knee osteoarthritis progression in rabbit model

Objective To investigate the time-dependent angiogenic activity of the subehondral bone and the role of angiogenesis in the pathogenesis of the advanced osteoarthritis （OA） using the rabbit OA model. Methods 30 New Zealand white rabbits were randomly divided into two groups：the anterior cruciate ligament transaction （ACLT） group （ n = 15 ） and the control group （ n = 15 ）. OA was surgically induced in the right knee. The rabbit knees were evaluated at 4, 8 and 12 weeks after ACLT, by gross observation, histological examination, immunohistochemistry, and vascular density number detection. The histologic evaluation was performed with safranin-O staining and OARSI score to assess the OA change; vascular endothelial growth factor （VEGF） was detected by the immunohistochemistry and the vascular density was calculated to confirm the vascular invasion at the osteochondral junction. Results The rabbits in the ACLT group after 4 weeks showed a typical OA pathological changes, such as the loss of surface integrity, fissuring and mircocracks, the loss of cartilage （by satanin-O staining ）. The exposed subchondral bone increased at 8 and 12 weeks. The OARSI scores of different time points were statistically significant （F = 440. 828, P 〈 0. 05 ） compared with the control group. The VEGF imnmnohistochemieal staining indicated positive results of the ACLT group. The vascular invasion numbers significantly increased in the ACLT group, compared to the control group and there were statistically significant differences between each of the time point （ F = 72. 733, P 〈 0. 05 ）. Conclusion The angiogenic activity of subchondral bone was elevated in the early stage to the advanced stage of OA and it is associated with the cartilage degeneration. The degree of vascular invasion into the osteochondral junction increases in a time- dependent manner with the progression of OA.