Duryea J, Zaim S, Genant H K
Osteoporosis and Arthritis Research Group, Department of Radiology, University of California, San Francisco 94143, USA.
Osteoarthritis Cartilage. 2003 Feb;11(2):102-10. doi: 10.1053/joca.2002.0866.
Minimum joint space width (mJSW) between the femoral condyle and tibial plateau is currently the principal radiographic outcome measure for knee osteoarthritis (OA). While mJSW measurement has been proven effective, there is a need for quantitative measures with greater sensitivity to OA so studies of disease modifying trials can be performed more quickly and with fewer subjects. Also, mJSW is a single outcome measure that does not reflect all disease changes. Here we present a study of new radiograph-based outcome measures to quantify OA progression.
Our goal is made possible by a software algorithm that delineates both the edge of the tibial plateau and the femoral condyle on digitized knee radiographs. We also developed a new coordinate system based on anatomical landmarks to facilitate measurement of the outcome measures. We studied measurements of joint space width (JSW) and average JSW at fixed locations along the joint interface. The outcome measures were tested using duplicate acquisitions made from 16 OA and 18 normal knees. Reproducibility was quantified by the root-mean square standard deviation and the coefficient of variation.
We found that the reproducibility for all outcome measures was better than or similar to that for mJSW. Despite a slightly higher reproducibility error for some new outcome measures compared to mJSW, they are potentially valuable since they reflect independent disease changes.
We have demonstrated new reproducible radiographic outcome measures to quantify OA progression with the potential to be an improvement over standard minimum joint space width.
股骨髁与胫骨平台之间的最小关节间隙宽度（mJSW）目前是膝关节骨关节炎（OA）主要的影像学结局指标。虽然mJSW测量已被证明有效，但仍需要对OA更敏感的定量指标，以便能更快地开展疾病修饰试验研究且所需受试者数量更少。此外，mJSW是单一的结局指标，无法反映所有疾病变化。在此，我们展示一项关于基于X线片的新结局指标以量化OA进展的研究。
通过一种软件算法实现了我们的目标，该算法可在数字化膝关节X线片上勾勒出胫骨平台和股骨髁的边缘。我们还基于解剖标志点开发了一种新的坐标系，以方便对结局指标进行测量。我们研究了关节间隙宽度（JSW）以及沿关节界面固定位置处的平均JSW的测量。使用从16个OA膝关节和18个正常膝关节重复采集的数据对结局指标进行测试。通过均方根标准差和变异系数对可重复性进行量化。
我们发现所有结局指标的可重复性均优于或类似于mJSW。尽管与mJSW相比，一些新结局指标的可重复性误差略高，但它们仍具有潜在价值，因为它们反映了独立的疾病变化。
我们已展示出可重复的新影像学结局指标来量化OA进展，有可能优于标准的最小关节间隙宽度。
