Lechler Philipp, Frink Michael, Gulati Aashish, Murray David, Renkawitz Tobias, Bücking Benjamin, Ruchholtz Steffen, Boese Christoph Kolja
Department of Trauma , Hand and Reconstructive Surgery, University of Giessen and Marburg, Marburg , Germany.
Acta Orthop. 2014 Aug;85(4):389-95. doi: 10.3109/17453674.2014.931196. Epub 2014 Jun 23.
Adequate restoration of femoral offset (FO) is critical for successful outcome after hip arthroplasty or fixation of hip fracture. Previous studies have identified that hip rotation influences the projected femoral offset (FOP) on plain anteroposterior (AP) radiographs, but the precise effect of rotation is unknown.
We developed a novel method of assessing rotation-corrected femoral offset (FORC), tested its clinical application in 222 AP hip radiographs following proximal femoral nailing, and validated it in 25 cases with corresponding computed tomography (CT) scans.
The mean FORC was 57 (29-93) mm, which differed significantly (p < 0.001) from the mean FOP 49 (22-65) mm and from the mean femoral offset determined by the standard method: 49 (23-66) mm. FORC correlated closely with femoral offset assessed by CT (FOCT); the Spearman correlation coefficient was 0.94 (95% CI: 0.88-0.97). The intraclass correlation coefficient for the assessment of FORC by AP hip radiographs correlating the repeated measurements of 1 observer and of 2 independent blinded observers was 1.0 and 1.0, respectively.
Hip rotation affects the FOP on plain AP radiographs of the hip in a predictable way and should be adequately accounted for.
股骨偏心距（FO）的充分恢复对于髋关节置换术或髋部骨折固定术后的成功预后至关重要。既往研究已证实髋关节旋转会影响髋关节前后位（AP）平片上的股骨偏心距投影（FOP），但旋转的精确影响尚不清楚。
我们开发了一种评估旋转校正股骨偏心距（FORC）的新方法，在222例股骨近端钉固定术后的髋关节AP平片上测试了其临床应用，并在25例相应的计算机断层扫描（CT）病例中进行了验证。
平均FORC为57（29 - 93）mm，与平均FOP 49（22 - 65）mm以及标准方法测定的平均股骨偏心距：49（23 - 66）mm相比，差异有统计学意义（p < 0.001）。FORC与CT评估的股骨偏心距（FOCT）密切相关；Spearman相关系数为0.94（95%CI：0.88 - 0.97）。通过髋关节AP平片评估FORC时，1名观察者重复测量以及2名独立盲法观察者测量的组内相关系数分别为1.0和1.0。
髋关节旋转以可预测的方式影响髋关节AP平片上的FOP，应予以充分考虑。
