Scott William W, Beall Douglas P, Eng John, Matthiesen Chance L, Prater Scott, Enis John
Clinical Radiology of Oklahoma, University of Oklahoma, 610 NW 14th, Oklahoma City, OK 73103, USA.
J Okla State Med Assoc. 2007 Dec;100(12):469-72.
To compare standing PA flexed (SPAF) knee radiographs of the knees with standing full-extension AP(SAP) radiographs for demonstration of narrowing of the articular cartilage of the knee joint and the presence and size of osteophytes and to determine if sclerosis is a predictor of the severity of joint space narrowing.
220 knees in 110 consecutive patients visiting the orthopaedic clinic with knee pain and having both SPAF radiographs and SAP radiographs at the same visit were evaluated by a musculoskeletal radiologist for cartilage narrowing in the knee joint using a scale 0-3 with 0= normal and 3= bone on bone. Osteophytes were also graded 0-3 and sclerosis as present or absent.
The subjects were patients of one of the authors (C.A.J) who ordered both types of radiographs on most of his patients.
In 47% of knees the SPAF radiograph showed narrowing more severe than the SAP radiograph. In 5% the SAP view showed narrowing more severe than the SPAF view. In the medial compartment the SPAF view showed significantly larger osteophytes than the SAP view. The osteophyte size difference was not significant in the lateral compartment. If sclerosis was present on the AP view, there was a greater than 80% chance that the SPAF view would show greater narrowing.
The SPAF radiograph frequently shows more cartilage narrowing in the knee joint than does the SAP view. It is valuable for routine use or when the clinical severity of arthritis in the knee joint seems to be greater than that demonstrated on the AP standing view. Sclerosis on the SAP view makes it especially likely that the SPAF view will show greater cartilage narrowing.
比较站立位屈膝后前位（SPAF）膝关节X线片与站立位伸直位前后位（SAP）X线片，以显示膝关节软骨狭窄情况、骨赘的存在及大小，并确定骨质硬化是否为关节间隙狭窄严重程度的预测指标。
对110例因膝关节疼痛到骨科门诊就诊且在同一次就诊时同时拍摄了SPAF和SAP X线片的连续患者的220个膝关节，由一名肌肉骨骼放射科医生使用0 - 3级评分标准（0 = 正常，3 = 骨对骨）评估膝关节软骨狭窄情况。骨赘也分为0 - 3级，并判断是否存在骨质硬化。
研究对象为其中一位作者（C.A.J）的患者，该作者为其大多数患者都开具了这两种类型的X线片。
47%的膝关节SPAF X线片显示的狭窄比SAP X线片更严重。5%的膝关节SAP X线片显示的狭窄比SPAF X线片更严重。在内侧间室，SPAF X线片显示的骨赘明显大于SAP X线片。外侧间室的骨赘大小差异不显著。如果AP位X线片存在骨质硬化，那么SPAF位X线片显示更严重狭窄的可能性大于80%。
SPAF X线片通常比SAP X线片显示出膝关节更多的软骨狭窄。它对于常规使用或当膝关节关节炎的临床严重程度似乎大于站立位前后位X线片所显示的程度时很有价值。SAP位X线片上的骨质硬化使得SPAF位X线片尤其可能显示出更严重的软骨狭窄。
