Kaliya-Perumal Arun-Kumar, Luo Chi-An, Yeh Yu-Cheng, Tsai Yi-Fang, Chen Michael Jian-Wen, Tsai Tsung-Ting
Department of Orthopedic Surgery, Spine Division, Bone and Joint Research Center, Chang Gung Memorial Hospital and University College of Medicine, Taoyuan, Taiwan.
Department of Orthopedic Surgery, Melmaruvathur Adhiparasakthi institute of Medical Sciences and Research, Melmaruvathur, Tamil Nadu, India.
Acta Ortop Bras. 2018;26(6):411-414. doi: 10.1590/1413-785220182606201444.
The Michigan State University (MSU) classification of lumbar disc herniation (LDH) is periodically used by various authors to classify disc herniation. We assessed the reliability of this classification system among orthopedic residents at our institute.
Fifty T2 axial-cut magnetic resonance images (MRI) corresponding to the level of maximal disc herniation from patients diagnosed with a single LDH were selected and distributed to six orthopedic residents. All six residents gave a specific rating for each image based on the MSU classification; in addition, three residents gave ratings on two different occasions. The degree of agreement among residents was analyzed by calculating inter-observer and intra-observer reliability using the Kappa statistic.
The inter-observer reliability among the six residents calculated as the Fleiss' Kappa was 0.422, which indicates moderate reliability. The intra-observer reliability of three selected residents calculated by Cohen's Kappa was 0.750, 0.772, and 0.859, which indicates substantial to almost perfect reliability. Variations in ratings were frequent in images portraying a broad-based disc herniation with spinal canal stenosis.
Our findings demonstrate moderate homogeneity of ratings given by residents; however, test-retest results proved the ratings to be consistent.
密歇根州立大学（MSU）的腰椎间盘突出症（LDH）分类法被不同作者定期用于对椎间盘突出症进行分类。我们评估了该分类系统在我院骨科住院医师中的可靠性。
选取50例经诊断为单一腰椎间盘突出症患者的T2轴位磁共振成像（MRI），这些图像对应最大椎间盘突出水平，并分发给6名骨科住院医师。所有6名住院医师均根据MSU分类法对每张图像给出具体评分；此外，3名住院医师在两个不同时间进行评分。通过使用Kappa统计量计算观察者间和观察者内可靠性来分析住院医师之间的一致性程度。
6名住院医师间的观察者间可靠性（以Fleiss' Kappa计算）为0.422，表明可靠性中等。3名选定住院医师的观察者内可靠性经Cohen's Kappa计算分别为0.750、0.772和0.859，表明可靠性较高至几乎完美。在描绘伴有椎管狭窄的宽基底椎间盘突出的图像中，评分差异频繁出现。
我们的研究结果表明住院医师给出的评分具有中等同质性；然而，重测结果证明评分是一致的。
