Weinstabl R, Muellner T, Vécsei V, Kainberger F, Kramer M
University Clinic of Traumatology, University of Vienna Medical School, Austria.
World J Surg. 1997 May;21(4):363-8. doi: 10.1007/pl00012254.
With magnetic resonance imaging (MRI) the surgeon has such an effective diagnostic tool in the diagnosis of a meniscal lesion that the times of diagnostic arthroscopy should be in the past. A total of 823 patients with clinically diagnosed meniscal lesions were divided into two groups: group A, 143 patients underwent MRI and 75 of those arthroscopy; group B, 680 patients, 201 (30%) of whom were operated after being only clinically examined. MRI was done on a Siemens Medical System Magnetom 1.5 Tesla with a 256 x 256 matrix. Spinal echo and gradient echo images were performed with slices of 2 to 4 mm thickness. All meniscal tears were graded according to Reicher and Crues, respectively. Grades III and IV were judged to be positive for a meniscal lesion. Arthroscopy was carried out under general anesthesia and the usual technique. The MRI revealed the following results: Medial meniscus: accuracy 95%, positive predictive value (PPV) 92%, negative predictive value (NPV) 95%, sensitivity 98%, and specificity 82%, lateral meniscus: accuracy 97%, PPV 92%, NPV 98%, sensitivity 94%, and specificity 98%. The overall values for MRI of the medial and lateral menisci combined were: accuracy 96%, PPV 93%, NPV 98%, sensitivity 96%, and specificity 90%. The clinical examination often failed to diagnose a meniscal lesion: accuracy 64%, PPV 59%, NPV 89%, sensitivity 96%, and specificity 33% for the medial meniscus. For the lateral meniscus the accuracy was 91%, PPV 61%, NPV 98%, sensitivity 89%, and specificity 91%. The overall values for the clinical investigation of the medial and lateral menisci combined were: accuracy 78%, PPV 60%, NPV 94%, sensitivity 93%, and specificity 62%. Investigation of all 201 patients operated from group B with MRI would have cost $160,800. The cost of 30% fewer arthroscopies would have been $562,800--in total $723,600. The operation of all 201 patients cost $804,000. Hence about $80,000 could have been saved by scanning all 201 patients and therefore reduce the rate of diagnostic arthroscopies.
借助磁共振成像（MRI），外科医生拥有了一种在诊断半月板损伤方面极为有效的诊断工具，使得诊断性关节镜检查的时代应该成为过去。共有823例临床诊断为半月板损伤的患者被分为两组：A组，143例患者接受了MRI检查，其中75例接受了关节镜检查；B组，680例患者，其中201例（30%）仅经过临床检查后就接受了手术。MRI检查使用的是西门子医疗系统公司的Magnetom 1.5特斯拉磁共振成像仪，矩阵为256×256。采用自旋回波和梯度回波成像，层厚2至4毫米。所有半月板撕裂均分别按照赖歇尔（Reicher）和克鲁斯（Crues）的标准进行分级。III级和IV级被判定为半月板损伤阳性。关节镜检查在全身麻醉下按照常规技术进行操作。MRI检查得出了以下结果：内侧半月板：准确率95%，阳性预测值（PPV）92%，阴性预测值（NPV）95%，敏感性98%，特异性82%；外侧半月板：准确率97%，PPV 92%，NPV 98%，敏感性94%，特异性98%。内侧和外侧半月板联合MRI检查的总体数值为：准确率96%，PPV 93%，NPV 98%，敏感性96%，特异性90%。临床检查常常无法诊断出半月板损伤：内侧半月板的准确率为64%，PPV 59%，NPV 89%，敏感性96%，特异性33%。外侧半月板的准确率为91%，PPV 61%，NPV 98%，敏感性89%，特异性91%。内侧和外侧半月板联合临床检查的总体数值为：准确率78%，PPV 60%，NPV 94%，敏感性93%，特异性62%。对B组中所有201例接受手术的患者进行MRI检查的费用将为160,800美元。减少30%的关节镜检查费用将为562,800美元——总计723,600美元。所有201例患者的手术费用为804,000美元。因此，通过对所有201例患者进行扫描，从而降低诊断性关节镜检查的比例，大约可以节省80,000美元。
