Case Western Reserve University, Department of Orthopaedic Surgery, 2500 Metrohealth Drive, Cleveland, Ohio 44109, USA.
Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, PO Box 208071, New Haven, Connecticut 06520-8071, USA.
Bone Joint J. 2014 Sep;96-B(9):1274-81. doi: 10.1302/0301-620X.96B9.34314.
Malpositioning of the trochanteric entry point during the introduction of an intramedullary nail may cause iatrogenic fracture or malreduction. Although the optimal point of insertion in the coronal plane has been well described, positioning in the sagittal plane is poorly defined. The paired femora from 374 cadavers were placed both in the anatomical position and in internal rotation to neutralise femoral anteversion. A marker was placed at the apparent apex of the greater trochanter, and the lateral and anterior offsets from the axis of the femoral shaft were measured on anteroposterior and lateral photographs. Greater trochanteric morphology and trochanteric overhang were graded. The mean anterior offset of the apex of the trochanter relative to the axis of the femoral shaft was 5.1 mm (sd 4.0) and 4.6 mm (sd 4.2) for the anatomical and neutralised positions, respectively. The mean lateral offset of the apex was 7.1 mm (sd 4.6) and 6.4 mm (sd 4.6), respectively. Placement of the entry position at the apex of the greater trochanter in the anteroposterior view does not reliably centre an intramedullary nail in the sagittal plane. Based on our findings, the site of insertion should be about 5 mm posterior to the apex of the trochanter to allow for its anterior offset.
在髓内钉插入过程中，如果大转子进钉点定位不当，可能会导致医源性骨折或复位不良。虽然冠状面进钉的最佳点已有很好的描述，但矢状面的定位却定义不明确。将 374 具尸体的配对股骨分别置于解剖位和内旋中立位以中和股骨前倾角。在前后位和侧位片上，在大转子的明显顶点处放置一个标记，测量大转子顶点相对于股骨干轴线的外侧和前侧偏移。对大转子形态和大转子悬垂进行分级。相对于股骨干轴线，解剖位和中立位时大转子顶点的前侧偏移平均值分别为 5.1mm（标准差 4.0）和 4.6mm（标准差 4.2）。顶点的外侧偏移平均值分别为 7.1mm（标准差 4.6）和 6.4mm（标准差 4.6）。前后位上大转子顶点处的进钉点位置并不能可靠地将髓内钉定位于矢状面的中心。基于我们的发现，插入部位应位于大转子顶点后方约 5mm 处，以允许其前侧偏移。
