股骨近端X线测量及其在髋关节置换中的临床意义

Radiological assessments of proximal femoral geometry and its clinical significance in hip arthroplasty

目的：探讨股骨大转子顶点与股骨头中心的关系作为髋关节置换调整下肢长度的参考的可靠性。方法选择2013年6至10月北京中日友好医院骨关节外科符合标准的骨盆正位X线370例，男160例，女210例，平均年龄47.6岁；使用影像归档和通信（ PACS）系统确定股骨头中心，作股骨近端的解剖轴线，分别作股骨头中心和大转子顶点到股骨解剖轴线的垂线，两个交点之间的距离为大转子顶点至股骨头中心的垂直距离或称为大转子高度（ GTH）。两个骨科主治医师分别对每个距离进行测量，大转子顶点位于股骨头中心上方认为是正值，在下方认为是负值。比较男、女GTH值及同一X线左、右侧GTH值。结果仅有6个大转子顶点位于股骨头中心下方，9个与股骨头中心同一水平，725个位于股骨头中心上方。其中有96.89％GTH在0～15 mm范围。男性GTH值大于女性[（7.5±4.1）mm比（6.9±3.7） mm，P＝0.032]，右侧的GTH值明显大于左侧[（7.6±3.9） mm比（6.7±3.8） mm， P＜0.001]。结论股骨头中心与大转子顶点不在相同水平，同一骨盆X线左、右侧距离关系不恒定，髋关节置换术中使用大转子顶点和股骨头中心的关系调节下肢长度时要慎重。

Objective To explore the reliability of the relationship between the tip of greater trochanter and the center of femoral head in restoring leg length discrepancy during hip arthroplasty . Methods From June 2013 to October 2013, 370 standard anterior-posterior pelvic radiographs were performed.There were 160 males and 210 females with a mean age of 47.6 years.Landmarks were selected by Picture Archiving and Communication Systems （ PACS ） as follows： the center of femoral head of concentric circles , anatomic axis of proximal femur , the lines perpendicular to anatomic axis of proximal femur through the tip of greater trochanter and the center of femoral head.The distance between two intersected points , i.e.vertical distance between the tip of greater trochanter and the center of femoral head , aka greater trochanter height （GTH）, was measured by two orthopedic surgeons respectively.If the tip of greater trochanter was above the center of femoral head , the distance was defined as positive.And the distance was negative if the tip of greater trochanter fell below the center of femoral head .The distance of male and female and that of right and left femurs were compared .Results Only 6 tips of greater trochanter were below the center of femoral head , 9 at the same level and 725 above the center of femoral head.And 96.89%of tips of the greater trochanter were at 0-15 mm above the center of femoral head.The difference between male and female （ P =0.032 ） and the difference between right and left sides were statistically significant （P＆lt;0.001）.Conclusion The center of femoral head is not at the same level as the tip of greater trochanter.And the distances of right and left tips of greater trochanter to the ipsilateral center of femoral head are not always at the same level.So it should be cautious to employ the relationship between the tip of greater trochanter and the center of femoral head in restoring leg length discrepancy during hip arthroplasty .