基于三维CT多平面重建股骨近段髓腔的形态学实验

Multiple-plane reconstruction of the proxinal femoral canal using three-dimensional CT scans: A morphological study

背景:股骨近段髓腔的形态学特点对于股骨假体的匹配和远期稳定性至关重要。但目前还没有基于三维CT多平面重建股骨近段髓腔的形态学研究。目的:分析国人近段股骨髓腔的总体三维形态学特点,用以指导假体设计和手术操作。方法:50件(25对)正常国人的股骨标本,由吉林大学基础医学院解剖学教研室提供。对股骨标本进行CT扫描和多平面重建,在矢状面、冠状面及横断面重建图像中选择标准化层面分别测量股骨前弓角、近段股骨髓腔长度、股骨距轴线与近段股骨髓腔轴线的夹角(股骨距矢状面倾角)、干骺端髓腔内壁倾角以及股骨颈前倾角。应用Pearson二元相关分析明确以上参数的相关性。结果与结论:近段股骨髓腔长度为(175.6±8.6)mm;股骨前弓角为(10.6±1.8)°;在经股骨距内缘层面、中份层面和外缘层面股骨距矢状面倾角分别为(12.7±1.2)°,(6.3±0.9)°,(0.3±0.06)°;干骺端髓腔内壁倾角为(18.8±2.7)°;股骨颈前倾角为(11.0±2.3)°。相关分析表明股骨前弓角和股骨颈前倾角呈显著正相关(r=0.749,P=0.014)。在矢状面上,由内侧向外侧股骨距轴线与近段股骨髓腔轴线逐渐趋向一致。虽然在外观上近段股骨在干骺端部位存在后弓,但近段股骨髓腔的轴线为直线,近段股骨髓腔无后弓。提示进行初次人工全髋关节置换,直柄假体更能够适应国人近段股骨髓腔的形态。干骺端髓腔内壁的较大倾角使其成为股骨近端应力承载的最重要部位,因此干骺端髓腔内壁倾角应作为假体选择和术前计划的重要参数。

BACKGROUND： The morphological characteristics of the proximal femoral canal are crucial for the fitting and long-term stability of the femoral stem, but there is still no morphological study on the multiple-plane reconstruction of the proximal femoral canal applying the three-dimensional CT scans. OBJECTIVE： To find out the three-dimensional morphological characteristics of the proximal femoral canal, which can be used as guidelines for operation and prosthesis design. METHODS： A total of 50 pieces （25 pairs） of normal Chinese corpse femurs were harvested from the Anatomy Department, School of Basic Medicine of Jilin University. CT scan and then multiple-plane reconstructions of these femurs were done. Standard planes were selected from the coronal, sagittal and axial reconstruction images, and the following parameters were measured： the bow angle of femur, the length of the proximal femoral canal, the inclination angle of calcar on the sagittal plane, the inclination angle of the medial wall of the metaphyseal canal and the anteversion angle of the femoral neck. Pearson binary correlation analysis was applied to clarify the correlation of these parameters. RESULTS AND CONCLUSIONS： The length of the proximal femoral canal was （175.6±8.6） mm; the bow angle was （10.6±1.8）°. On the sagittal plane the inclination angles of calcar in the medial, middle and lateral part were （12.7±1.2）°, （6.3±0.9）° and （0.3±0.06）° respectively. The inclination angle of the medial wall of the metaphyseal canal was （18.8±2.7）° and the anteversion angle was （11.0±2.3）°. Correlation analysis showed a positive correlation between the bow angle and the anteversion angle. On the sagittal plane the axis of the calcar rotated toward the axis of the proximal femoral canal from medial to lateral. Although the proximal femur shows a bowing appearance, the proximal femoral canal is straight. For primary total hip arthroplasty, straight femoral stem fits better the proximal Chinese femoral canal. The inclination angle of the medial wall of the metaphyseal canal should use an important parameter for prosthesis selection.