Wolfe Frederick, Lane Nancy E, Buckland-Wright Chris
National Data Bank for Rheumatic Diseases and University of Kansas School of Medicine, Wichita, USA.
J Rheumatol. 2002 Dec;29(12):2597-601.
Current radiographic evaluation of knee osteoarthritis (OA) depends primarily on the presence and severity of joint space narrowing (JSN) and osteophytes. Radiographic JSN is a function of the actual JSN caused by articular cartilage loss and the observable JSN artifactually caused when the tibial and femoral surfaces diverge due to variations in patient's knee position. Views yielding the greatest JSN are the most accurate. Osteophytes are also dependent on positioning. This study investigated the consequences of positioning on JSN and osteophytes in clinical studies in which the outcome of OA knee is scored.
In total, 1105 patients underwent 1175 paired radiographic examinations using weight-bearing (WB) standard anterior-posterior (AP) extended knee views (AP-WB), semiflexed WB posterior-anterior views with the knee in contact with the film and the 1st metatarsophalangeal (MTP) joint under the film plane (MTP) (method of Buckland-Wright), and WB PA views with the tip of the great toe at the film plane, 20 degrees of knee flexion and 5 degrees downward angulation of the x-ray tube (schuss-tunnel view). Careful attention was given to proper positioning. JSN and osteophytes were scored on a 0-3 scale.
JSN was significantly greater by the MTP and schuss-tunnel methods than by the AP-WB method, but no difference was found between the MTP and schuss-tunnel methods. In addition, disagreement was identified in 34% of MTP and AP-WB scores. In 69.3% of disagreements the scores were more abnormal in the MTP view. When the disagreements were studied, the mean MTP score was 1.68 compared to 1.12 for the AP-WB score. Fifty-seven knees were scored as 3 by the MTP view and as 2 by the AP-WB, and 8 knees were scored as 3 by the AP-WB view and 2 by the MTP view. Little difference in osteophytes was noted among the 3 methods, although fewer osteophytes were identified by the schuss-tunnel method than the AP-WB method.
Using the clinical reading methods of this study, the MTP and schuss-tunnel views were equivalent when compared to each other. When compared with the AP-WB view, the schuss-tunnel view resulted in a lower osteophyte score. These results, based on clinical readings, are similar to previous computerized analyses that indicated that the MTP and schuss-tunnel views were superior to the AP-WB, but that the MTP view was superior to the schuss-tunnel view.
目前膝关节骨关节炎（OA）的影像学评估主要取决于关节间隙变窄（JSN）和骨赘的存在及严重程度。影像学上的JSN是由关节软骨丢失导致的实际JSN以及因患者膝关节位置变化致使胫股关节面分离而人为造成的可观察到的JSN假象共同作用的结果。产生最大JSN的投照角度最为准确。骨赘也取决于投照位置。本研究调查了在对OA膝关节结局进行评分的临床研究中，投照位置对JSN和骨赘的影响。
总共1105例患者接受了1175次配对的影像学检查，采用负重（WB）标准前后位（AP）膝关节伸展位投照（AP-WB）、膝关节半屈曲位且与胶片接触、第1跖趾关节（MTP）位于胶片平面下方的负重后前位投照（MTP）（巴克兰-赖特方法）以及大脚趾尖位于胶片平面、膝关节屈曲20度且X线球管向下成角5度的负重前后位投照（滑行车隧道位投照）。仔细注意正确的投照位置。JSN和骨赘按0-3分进行评分。
MTP法和滑行车隧道位投照法所显示的JSN显著大于AP-WB法，但MTP法和滑行车隧道位投照法之间未发现差异。此外，在34%的MTP评分与AP-WB评分中发现存在分歧。在69.3%的分歧中，MTP位投照的评分更异常。在研究这些分歧时，MTP评分的平均值为1.68，而AP-WB评分为1.12。57个膝关节MTP位投照评分为3分而AP-WB位投照评分为2分，8个膝关节AP-WB位投照评分为3分而MTP位投照评分为2分。3种方法在骨赘方面差异不大，尽管滑行车隧道位投照法所发现的骨赘比AP-WB法少。
采用本研究的临床读片方法，MTP位投照和滑行车隧道位投照相互比较时效果相当。与AP-WB位投照相比，滑行车隧道位投照的骨赘评分更低。基于临床读片的这些结果与先前的计算机分析结果相似，先前分析表明MTP位投照和滑行车隧道位投照优于AP-WB位投照，但MTP位投照优于滑行车隧道位投照。
