利用HHGS和OOCHAS评分评价兔前交叉韧带断裂后膝骨关节炎软骨损伤程度的研究

Comparison of Feasibility of HHGS and OOCHAS in Evaluating Knee Osteoarthritis after Anterior Cruciate Ligament Rupture in Rabbits

目的：研究两种软骨组织学评分方法 Histologic/Histochemical Grading System（HHGS）和OARSI Osteoarthritis Cartilage Histopathology Assessment System（OOCHAS）对兔前交叉韧带断裂后骨关节炎早期软骨损伤评价的不同,选择更适合早期软骨损伤评价的组织学评分标准。方法：取48只成年新西兰大白兔（2.5~3 kg）,切断左膝前交叉韧带建立骨关节炎（OA）模型（实验组）,右膝为假手术组（对照组）。分别于术后2、4、6、8周随机处死12只兔子,分别取实验组与对照组胫骨平台负重区软骨行大体观评分、核磁检查、HE和甲苯胺蓝染色,利用HHGS和OOCHAS对组织切片进行软骨损伤评价,并分析两种标准之间的差异。结果：大体观和核磁结果：术后第2周无明显软骨损伤,术后第4周出现早期OA软骨损伤,术后第6和8周出现中晚期OA软骨损伤。组织学评分结果：两种评分标准对实验组术后2、6和8周的软骨损伤程度评价一致,但对术后第4周的评价存在差异,HHGS评分结果显示,12膝中9膝为中期OA软骨损伤,3膝为早期OA软骨损伤;OOCHAS评分显示,1膝为中期OA软骨损伤,11膝为早期OA软骨损伤,配对卡方检验结果：P=0.021,表明两者构成比存在差异。kappa=-0.176（〈0.02为一致性差）,表明两种方法在评价早期软骨损伤时一致性较差。与HHGS评分相比,OOCHAS评分结果与大体观和核磁检查结果更一致。结论：本动物实验研究表明OOCHAS评分适合前交叉韧带断裂后早期骨关节炎软骨损伤的评价。

Objective To compare the feasibility of histologic/histochemical grading system（HHGS） and the OARSI osteoarthritis cartilage histopathology assessment system（OOCHAS） in evaluating osteoarthritis（OA）after anterior cruciate ligament rupture in rabbits in order to choose the better one for early evaluating cartilage injury. Methods 48 mature New Zealand white rabbits were used in this study. The left ACL of the rabbits was resected and served as experimental group,and the contralateral joints of the rabbits received medial arthrotomy and served as control group. Every 12 rabbits were randomly killed respectively at week2,4,6,and 8 after surgery. The changes in articular cartilage of medial tibial plateau on tissue section were evaluated by HHGS and OOCHAS. Results Macroscopic observation and MRI showed that there was no degeneration of cartilage in at week 2 after surgery,early OA appeared at week 4,and moderate and severe OA appeared at week 6 and 8 after surgery. There was moderate and mild cartilage degeneration in 9 of 12knees（75%）and early cartilage degeneration in 3 of 12 knees（25%）at week 4 evaluated by HHGS,whereas there was moderate and mild cartilage degeneration in 1 of 12 knees（8.3%）and early cartilage degeneration in11 of 12 knees（91.67%）at week 4 evaluated by OOCHAS. The results of OOCHAS score matched well with the results of macroscopic observation and MRI. There were significant differences in constituent ratio（P =0.021）and in consistency（kappa =-0.176）in evaluation of early cartilage injury between the two systems.Conclusion Results suggest that OOCHAS is suitable for evaluating early cartilage degeneration of OA after ACL rupture in rabbits.