光学相干断层成像在兔膝关节软骨厚度测量中的应用

目的：比较光学相干断层成像(OCT)与不脱钙冰冻切片法测量新西兰大白兔膝关节软骨厚度数值,探索使用 OCT 无创测量兔膝关节软骨厚度的可行性。方法选择标准化饲养成年雄性新西兰大白兔50只(100个膝关节),以直径2 mm 环形钻标记膝关节股骨内侧髁负重区软骨面,取中心点、+0.5 mm、-0.5 mm 3个测量点,先后采用 OCT、不脱钙冰冻切片镜下测量采集软骨厚度数据,比较2组数据值并绘制2种测量方法在3个测量点的 Bland-Altman 图检验2种测量方法的一致性。结果中心点、+0.5 mm、-0.5 mm 3个测量点 OCT 测量结果(296.5±1.6)μm、(302.6±3.5)μm、(287.9±5.6)μm,不脱钙冰冻切片测量结果(278.4±1.9)μm、(290.3±5.9)μm、(280.3±4.6)μm。3个测量点的 Bland-Altman 图中,差值的均数以及差值的95%分布范围分别为：18.11(16.65,19.56)μm、12.4(5.5,19.2)μm、7.4(2.8,12.0)μm,3个测量点计算组内相关系数(ICC)分别为0.93(95%CI：0.89~0.95,P <0.0001)、0.84(95%CI：0.77~0.89,P <0.0001)、0.91(95%CI：0.87~0.94,P <0.0001)。结论以不脱钙冰冻组织切片显微镜下测量作为标准参照,OCT 技术用于兔膝关节软骨厚度测量具有可行性,其优势在于测量兔膝关节软骨厚度快速无创、重复性好,可为组织工程软骨修复关节软骨缺损动物实验提供数据参考。

The application of optical coherence tomography to measure the thickness of rabbit knee joint cartilage

Objective To study the feasibility of the measurement of the thickness of rabbit knee joint cartilage by comparing the optical coherence tomography (OCT)and the undecalcified frozen section method on respectively measure the thickness of New Zeal-and white rabbit’s knee cartilage.Methods 50 standardized cultivation,adult and male New Zealand white rabbits (100 knees) were selected in this study.The measurement point was at the knee weight-bearing area of the medial femoral condyle with a 2 milli-meter diameter trephine,and the cartilage thickness data at the same center point and ±0.5 mm from the center were obtained.OCT and freeze-sectioning method were adopted at each site,respectively.The difference between OCT and histological method was com-pared and Bland-Altman plot was constructed.Results The thickness results of the center,+0.5 mm,-0.5 mm points were (296.5± 1.6)μm,(302.6± 3.5)μm,(287.9±5.6)μm by OCT,(278.4±1.9)μm,(290.3±5.9)μm,(280.3±4.6)μm by freeze-sectio-ning method,respectively.In Bland-Altman diagram,mean difference and 95% confidence interval were 18.1 1 (1 6.65,1 9.56)μm, 12.4 (5.5,1 9.2)μm,7.4 (2.8,12.0)μm.Intra-class correlation coefficients(ICC)for resemblance between the 2 techniques were 0.93(95%CI:0.89-0.95,P <0.000 1),0.84(95%CI:0.77-0.89,P <0.000 1),0.91(95%CI:0.87 -0.94,P <0.000 1),respec-tively.Conclusion As compared with the measurement of undecalcified frozen section,OCT for the rabbits’knee joint cartilage thickness measurement is feasible with the advantages of noninvasiveness,good repeatability.OCT can provide data reference in ani-mal experiments of cartilage tissue engineering for articular cartilage defect repair.