髌股关节切线位新摄影术的研究

A new tangential radiographic view of patello-femoral joint

目的 探讨对髌股关节切线位摄影的新技术。方法 在 6 2例病人膝关节侧位平片上测量了膝关节屈曲角 ,髌骨后缘线与股骨长轴、胫骨长轴及胫骨前皮肤线之间的夹角。分析其间的相互关系 ,得出髌骨后缘线和股骨之间夹角与膝关节屈曲角成直线相关关系 ,其直线方程为 :^y =2 +0 8x。髌骨后缘线与胫骨长轴及胫骨前皮肤线之间的夹角的平均值分别为 3 3°和 12 7°。根据测量结果研制出辅助摄影台 ,提出了用仰卧位屈膝 30°上下投照的新方法。结果 应用此方法成功地摄取了 40例病人的 5 8个髌股关节 ,此 5 8个髌股关节切线位X线片的显示情况按优、良、中、差四级评判 ,其中优 18个 (占 31% ) ,良 30个 (占 5 2 % ) ,中 8个 (占 14% ) ,差 2个 (占 3% )。优良率达 83%。造成照片质量差的原因是由于髌韧带过短而导致髌胫前角过小或成负角 ,髌股关节切线位摄影困难。结论 此新的摄影位置具有准确、舒适、简便易行及稳定的特点 。

Objective To find a new method of tangential view of patello femoral joint. Methods 62 cases of lateral knee radiographs were studied. The knee flexion angles, patello femoral angles, patello tibial angles and frontal patello tibial angles were measured and their relationships analyzed. The knee flexion angles and the patello femoral angles had linear relationship with a linear equation = 2 + 0.8x . The angles of posterior patellar line with tibial long axis and frontal tibial line were 3.3° and 12.7°respectively. According to the measurement results, an accessary positoning table was designed. The patients′ patello femoral joints were examined with the knee flexed at an angle of 30°. The patients were in supine position and the central X ray was angled at 73°vertically toward the film. Results 58 patello femoral joints of 40 patients were radiographically studied (10 males, 30 females) .All radiographs were classified into 4 degrees as Grade A, B, C and D. Eighteen cases were Grade A (31%), 30 cases were Grade B(52%), 8 cases were Grade C(18%)and 2 Grade D(3%).The reason for Grade D was due to small or negtive anterior patellotibial angles. Conclusion This new method of tangential view of patello femoral joint is accurate, comfortable and simple and could be used as routine examination for patello femoral joint diseases.