Clement Nicholas D, Hamilton David F, Burnett Richard
Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK.
Arthritis. 2014;2014:121069. doi: 10.1155/2014/121069. Epub 2014 Feb 11.
Purpose. To describe a reliable method of predicting native joint line and posterior condylar offset (PCO) using true lateral digital radiographs of the distal femur. Methods. PCO was measured relative to a line drawn parallel to the posterior cortex of the distal femur and the joint line was measured from the posterior condylar flare to the articular surface. A ratio was then calculated for these measurements relative to the width of the femur at the level of the flare. Two independent observers measured PCO and joint line ratio for 105 radiographs of the different knees and one repeated these measurements after one week. Results. There was a significant correlation between the width of the femoral diaphysis at the level of the posterior condylar flare with joint line (P = 0.008) and PCO (P = 0.003). Joint line and PCO could be predicted within 4 mm and 2 mm, respectively, using the identified ratio between the width of the femoral diaphysis at the level of the posterior condylar flare with measured joint line and PCO. The inter- (P < 0.001) and intra- (P < 0.001) observer reliability for these ratios were high. Conclusion. These ratios could be used to predict the native joint line and PCO.
目的。描述一种使用股骨远端的真实侧位数字X线片预测自然关节线和后髁偏移（PCO）的可靠方法。方法。相对于平行于股骨远端后皮质绘制的线测量PCO，并从后髁突起到关节面测量关节线。然后针对这些测量值计算相对于髁突水平处股骨宽度的比率。两名独立观察者对105张不同膝关节的X线片测量PCO和关节线比率，一名观察者在一周后重复这些测量。结果。在髁突水平处股骨干宽度与关节线（P = 0.008）和PCO（P = 0.003）之间存在显著相关性。使用在髁突水平处股骨干宽度与测量的关节线和PCO之间确定的比率，分别可以在4毫米和2毫米内预测关节线和PCO。这些比率的观察者间（P < 0.001）和观察者内（P < 0.001）可靠性很高。结论。这些比率可用于预测自然关节线和PCO。
