探讨3D影像下顺行髓内钉理想置入点与正常成年人股骨大转子最高点的联系

目的:利用3D影像分析正常成年人股骨大转子最高点与髓腔中线的关系,为顺行髓内钉理想置入点的确定提供参考。方法:检索2016年1月至2017年1月行股骨全长CT检查的正常成年人107例,男64例,女43例;年龄(51.7±16.4)岁;左侧54例,右侧53例。利用Volume Viewer软件重建3D影像,根据股骨大转子形态分为前峰型(anterior apex,AA),后峰型(posterior apex,PA),中峰型(middle apex,MA),无峰型(none apex,NA)4组;冠状及矢状面上根据前倾角度分别调整股骨至标准颈干角位(apparent neck shaft angle,ANSA)及真颈干角位(true neck shaft angle,TNSA),分别记为C-ANSA,C-TNSA,S-ANSA,S-TNSA,测量各组在上述4个位置上股骨髓腔中线至股骨大转子最高点的垂直距离(vertical distance,VD),并对测得的VD值进行统计学分析;多元线性回归法分析临床资料与VD值的关系。结果:(1)4组4个位置对应VD值比较,AA组、MA组在S-ANSA上的VD值比较差异无统计学意义;AA、MA、NA组在C-ANSA和C-TNSA上的VD值比较差异无统计学意义。(2)矢状面2个位置VD值比较,AA、MA、NA组VD值比较差异有统计学意义;冠状面2个位置VD值比较,PA、 NA组比较差异有统计学意义。(3)经多元线性回归获得SANSA和S-TNSA位置上VD值的预测方程,S-ANSA上R=0.343,F=3.409,P=0.012;S-TNSA上R=0.317,F=2.846,P=0.028,其中颈干角和性别是矢状位上VD值的影响因素,而与冠状面上2个位置的VD值大小无明显差异。结论 :(1)以股骨大转子最高点为解剖标志确定正常成年人股骨髓内钉进针点,须辨别股骨大转子形态以及明确观测体位后再对矢状面上前后偏移及冠状面的横向偏移进行估计。(2)矢状面上的前后偏移随着颈干角的增大而有所增大,且女性前后偏移程度较男性小。

Correlation between highest point of greater trochanter and the ideal entry point for antegrade femoral nailing by three-dimensional images

Objective: To provide reference of the ideal entry point for antegrade femoral nailing according to analysis correlation between highest point of greater trochanter and the middle line of the medullary cavity in adults by three-dimensional images.Methods: From January 2016 to January 2017,107 adults who underwent continuous computed tomography(CT) scans were ultimately enrolled,including 64 males and 43 females with an average age of(51.7±16.4) years old;54 patients on the left side and 53 patients on the right side. Three-dimensional images were built by using image-processing software (Volume Viewer) to reconstruct geometry of cortex and medullary canal. All people were grouped according to different femoral greater trochanter morphology,such as anterior apex(AA),posterior apex(PA),middle apex (MA) and none apex (NA). Forwards inclination was adjusted to apparent neck shaft angle (ANSA) and true neck shaft angle (TNSA) on the coronal and saggittal view,recorded as C-ANSA,C-TNSA,S-ANSA,S-TNSA respectively,vertical distance from the middle line of femur medullary cavity to the highest point of greater trochanter of femur on the 4 positions were measured and performed statistical analysis,multiple linear regression was applied to analysis relationship between clinical data and VD value.Results: (1)Comparison of VD value among 4 groups on the 4 positions,there were no difference in VD value between AA and MA groups on the S-ANSA position;and no differences in VD value among AA,MA and NA groups on the C-ANSA and C-TNSA position. (2)There were differences in VD value among AA,MA and NA groups on the sagittal plane;while had difference in VD value between PA and NA group on the coronal plane. (3)Prediction equation of VD value on S-ANSA and S-TNSA position by multiple linear regression showed R=0.343,F=3.409,P=0.012 on the S-ANSA position;R=0.317,F=2.846,P=0.028 on the S-TNSA position; neck shaft angle and sex were risk factors of VD value on the sagittal plane,while no difference in VD value on the coronal position.Conclusion: (1)When indentify insertion point in adult femoral nail according to the highest point of greater trochanter as anatomic landmark,the morphology of greater trochanter of femur should be distinguished to certain observation position,then evaluate migration before and after on the sagttial plane and lateral offset on the coronal plane. (2)Migration before and after on the sagttial plane is increase with increase of neck shaft angle,and the degree of migration of female before and after is less than that of male.