常用股骨髓内定位杆进针点选择的CT三维重建评价

SELECTION OF COMMON ENTRY POINTS FOR FEMORAL INTRAMEDULLARY POSITIONING ROD BASED ON CT THREE-DIMENSIONAL RECONSTRUCTION

目的通过CT三维重建从常用股骨髓内定位杆进针点中寻找操作简便且精确可靠的髓内定位进针点。方法选取60例膝关节炎病人(100膝)进行CT扫描,利用Mimics Research 21.0软件三维重建功能获得股骨髓内定位理论进针点(点A),测量其与后交叉韧带(PCL)止点上方1 cm(点B)、髁间凹中点(点C)、通髁线和Whiteside’s线交点(点D)3个常用进针点之间的距离AB、AC、AD。结果股骨髓内定位杆进针点的位置靠近股骨内侧髁,AB、AC、AD分别为(4.06±1.09)、(13.04±1.90)、(18.25±2.47)mm,各距离间比较差异有统计学意义(F=1662.38,P<0.01)。男性左右膝AB、AC、AD差异无统计学意义;女性左右膝AB、AD差异无统计学意义(P>0.05),AC左右膝差异有统计学意义(t=2.64,P<0.05)。男性与女性AB、AC、AD比较差异均有统计学意义(t=4.87~6.71,P<0.01)。结论以滑车点作为PCL止点时,其上方1 cm处确定的髓内进针点可以更精确地进行股骨远端截骨,为术后获得良好的股骨假体力线提供保障。

Objective To investigate the simple,accurate,and reliable intramedullary positioning entry point among the entry points of femoral intramedullary positioning rod based on CT three-dimensional reconstruction.Methods A total of 60 patients(100 knees)with knee arthritis were selected for CT scan.The three-dimensional reconstruction function of Mimics Research 21.0 was used to obtain the theoretical entry point(Point A)of femoral intramedullary positioning and measure the distances between Point A and 1 cm above the femoral endpoint of the posterior cruciate ligament(Point B),between Point A and the midpoint of the intercondylar notch(Point C),and between Point A and the point of intersection of the femoral transepicondylar axis and the Whiteside’s line(Point D),which were expressed as AB,AC,and AD,respectively.Results The theoretical position of the entry point of femoral intramedullary positioning rod was close to the medial femoral condyle,and AB,AC,and AD were(4.06±1.09),(13.04±1.90),and(18.25±2.47)mm,respectively,with no significant difference between AB,AC,and AD(F=1662.38,P<0.01).In male patients,there were no significant differences in AB,AC,and AD between the left and right knees;in female patients,there were no significant differences in AB and AD between the left and right knees(P>0.05)and there was a significant difference in AC between the left and right knees(t=2.64,P<0.05).There were significant differences in AB,AC,and AD between the male and female patients(t=4.87-6.71,P<0.01).Conclusion When the trochlear point is used as the femoral endpoint of the posterior cruciate ligament,the intramedullary entry point determined at 1 cm above the femoral endpoint of the posterior cruciate ligament can help to achieve more accurate distal femur osteotomy and provide guarantee for obtaining a good line of force of femoral prosthesis after surgery.