Dupuis D E, Beynnon B D, Richard M J, Novotny J E, Skelly J M, Cooper S M
University of Vermont College of Medicine, Burlington, VT 05405, USA.
Osteoarthritis Cartilage. 2003 Oct;11(10):716-24. doi: 10.1016/s1063-4584(03)00158-4.
To quantify the precision and accuracy of measurements of joint space width (JSW) and joint space narrowing (JSN) from the medial tibiofemoral compartment of knee radiographs using a simple and easily adaptable protocol.
Radiographs of a caliper (a surrogate for JSW) were obtained to determine the precision limits of the system under ideal conditions. Bilateral knee radiographs from 10 healthy volunteers were obtained at three different times using the metatarsophalangeal (MTP) semi-flexed view posterior-anterior position without fluoroscopy. A backlit digitizing tablet and three manual methods were used to measure JSW and analyses of precision were performed. The accuracy of measuring change in JSW (a measure of JSN) was estimated from radiographs of cadaver knees that were placed in a servo-hydraulic device that moved the femur relative to the tibia through known intervals.
Radiographic measurements of the caliper inter-blade distance were comparable to the resolution limits of the backlit digitizing tablet (0.025 mm). Repeated radiography of healthy subject knees produced JSW standard deviation (SD) measurements of 0.08 mm by the median SD method, and 0.11 mm by repeated measures analysis. The accuracy of JSN measurements in the cadaver knees as a mean difference from the known reference value was 0.09 mm.
The results indicate a high level of precision in measurements of JSW from MTP semi-flexed view knee radiographs of normal volunteers. Reproducibility was attained through careful subject positioning without fluoroscopy and the use of a backlit digitizing tablet. From the cadaver study we can predict that greater than 0.13 mm of measured JSN represents actual or true change in JSN. This radiographic technique can be used as a primary measure for early knee osteoarthritis (OA) when cartilage thickness is decreasing and limited bony remodeling has occurred.
采用一种简单且易于应用的方案，量化膝关节X线片内侧胫股关节间隙宽度（JSW）和关节间隙变窄（JSN）测量的精度和准确性。
获取卡尺（JSW的替代物）的X线片，以确定系统在理想条件下的精度极限。在无荧光透视的情况下，采用跖趾关节（MTP）半屈曲位后前位，于三个不同时间获取10名健康志愿者的双侧膝关节X线片。使用背光数字化平板和三种手动方法测量JSW，并进行精度分析。通过将尸体膝关节X线片置于伺服液压装置中，使股骨相对于胫骨以已知间隔移动，来估计测量JSW变化（JSN的一种测量方法）的准确性。
卡尺叶片间距离的X线测量值与背光数字化平板的分辨率极限（0.025mm）相当。健康受试者膝关节的重复X线检查，通过中位数标准差法得出JSW标准差（SD）测量值为0.08mm，通过重复测量分析得出为0.11mm。尸体膝关节中JSN测量的准确性，作为与已知参考值的平均差值为0.09mm。
结果表明，从正常志愿者的MTP半屈曲位膝关节X线片测量JSW具有很高的精度。通过在无荧光透视的情况下仔细进行受试者定位并使用背光数字化平板，实现了可重复性。从尸体研究中我们可以预测，测量到的JSN大于0.13mm代表JSN的实际或真实变化。当软骨厚度减少且发生有限的骨质重塑时，这种X线技术可作为早期膝关节骨关节炎（OA）的主要测量方法。
