转子间骨折中股骨干近侧断面环周皮质的CT影像学测量及其临床意义

The remnant circumferential cortex in pertrochanteric femoral fractures: CT image study and clinical implications

目的探讨转子间骨折中股骨干近侧断面环周皮质在CT三维影像上的形态学特征,为股骨转子间骨折的皮质支撑复位提供结构基础和解剖学依据。方法收集80例AO/OTA分类31-A1、A2型股骨转子间骨折,通过CT扫描和三维重建,导入Mimics软件,进行骨折块分割与模拟复位后,沿与股骨干轴线呈130°角方向的斜断面,测量股骨干近侧断面残留的环周皮质长度及其前侧壁、外侧壁、后侧壁构成的宽度、以及前后壁皮质断面夹角。结果 A1型骨折21例,环周皮质长度平均为88.7 mm;前侧、外侧、后侧皮质宽度为36.9,36.9,27.3 mm;前后皮质断面夹角16.2°。A2型骨折59例,环周皮质长度平均为60.0 mm;前侧、外侧、后侧皮质宽度为32.3,27.4,9.2 mm;前后皮质断面夹角40.2°。A2型骨折残留环周皮质长度显著小于A1型骨折(P<0.01)。其中后侧皮质宽度变异度最大,前侧皮质宽度变异度较小,基本维持稳定(C.V分别为75.5%、20.0%)。结论转子间骨折中股骨近侧断面残留的环周皮质长度在A1与A2型间存在显著差异。后侧皮质宽度明显为小且变异度大,但前侧皮质宽度基本稳定,可作为骨折复位中获得皮质支撑砥住的主要结构。

Objective To investigate the morphological features of circumferential proximal cortex in pertrochanteric fractures by CT-images,and providing structural basis and anatomical reference for the cortical support reduction in pertrochanteric fractures. Methods Eighty cases of AO/OTA 31-A1 and A2 pertrochanteric fractures were enrolled in this study. The CT scans of the cases were collected and the 3 D-CT images were reconstructed by using the Mimics software. Fractures were reconstructed and simulated by 3 DCT. With the angle between the femoral shaft axis and the head-neck axis maintained at 130 degrees, the circumference of remnant circumferential cortex, width of its anterior part, lateral part, posterior part, and angle of the line between anterior and posterior broken-ends were measured. Results Twenty-one cases belong to type A1, the average circumferential cortex length was 88.7 mm;anterior, lateral and posterior circumferential cortex widths were 36.9 mm, 36.9 mm and 27.3 mm, respectively;and broken-ends line angle was 16.2°. 59 cases in type A2, the average circumferential cortex length was 60.0 mm;anterior, lateral and posterior circumferential cortex widths were 32.3 mm, 27.4 mm and 9.2 mm, respectively;and broken-ends line angle was 40.2°. The length of circumferential cortex in type A1 was significantly longer than that in A2(P<0.01). On the whole, the posterior cortex had the largest variation, while anterior cortex was much more stable and showed the lowest variation(C.V were 75.5% and 20.0%). Conclusions There are significant differences between type A1 and A2 in circumferential cortical morphology of the proximal femur. The posterior cortex width is small and highly variable. While the anterior cortex width is much more longer and basically stable, which could be used as the main structure for the cortical support reduction.