股骨近端髓内钉治疗股骨粗隆间骨折的影像学分析

Radiographic analysis of treatment of inter-trochanteric fractures using proximal femoral nails

目的:建立一种股骨近端三维解剖形态的测量方法,研究Inter TAN髓内钉和股骨近端防旋髓内钉(proximal femoral nail anti-rotation,PFNA)手术对股骨近端解剖形态的影响。方法:利用Mimics等计算机辅助设计(computer assisted design,CAD)软件,建立一种在三维条件下,测量股骨近端三维(3 dimensional,3D)解剖形态的方法,并完成信度实验。收集40例股骨粗隆间骨折患者行Inter TAN和PFNA术后的CT数据,测量术后健侧和患侧的2D、3D前倾角和颈干角,髓内钉2D、3D前倾角。利用组内相关系数(intra-class correlation coefficient,ICC)检验股骨颈前倾角、颈干角等数据间的一致性,成对t检验比较成对数据的差异。结果:所建立测量方法的观察者间和观察者内信度均较高(ICC均大于0.9)。配对t检验显示不同髓内钉术后患侧前倾角与健侧前倾角相比差异均无统计学意义,一致性检验显示,患侧和健侧的2D、3D前倾角之间并无一致性(P分别为0.099和0.055);但髓内钉2D、3D前倾角和患侧相应的2D、3D前倾角之间的一致性较好(总体ICC分别为0.81和0.8,P值均小于0.001)。PFNA组术后患侧前倾角与健侧的差值大于15°者占57%,明显高于Inter TAN组的16%,配对t检验显示,PFNA术后的患侧和健侧的2D和3D颈干角之间差异无统计学意义(P值分别为0.925和0.367),Inter TAN术后患侧的2D和3D颈干角均明显小于健侧,差异有统计学意义(P值分别为0.033和0.009)。结论:通过对两种髓内钉术后股骨近端解剖形态的测量发现,与Inter TAN相比,PFNA术后股骨颈前倾角变化较大,两种髓内钉的前倾角与术后患侧股骨颈前倾角均有较强的相关性。

Objective：To establish a reliable approach for measuring proximal femoral 3 dimensional anatomy, and to compare post-operative differences of proximal femoralanatomy in the inter-trochanter fractures with two kinds of antegrade nailings.Methods： Some computer assisted design （ CAD ） soft-wares, e.g.Mimics, were used to establish a reliable approach for measuring proximal femoral 3 dimen-sional （3D） anatomy.Intra-class correlation coefficient （ ICC） was used to test the reliability of intra-and inter-observers.The post-operative pelvic CT data of 19 cases of inter-trochanter fracture patients treated with InterTAN nailing and 21 cases of inter-trochanter fracture patients treated with proximal femo-ral nail anti-rotation （ PFNA） were retrospectively analysed and used to measure bilateral proximal femo-ral anatomical parameters, including 2D and 3D femoral neck-shaft （ NS） angle and femoral neck ante-version （NA） angle, and 2D and 3D anteversion angles of the intramedullary （IM） nailings.ICC was used to test the consistency of the NA angles in the different groups, and the paired student T-test was used to test the differences of the paired quantitative data.Results：The established measurement method hasdexcellent consistency within the intra-and inter-observers, with all the ICCs higher than 0.9.The paired student T-test showed no significant difference between the post-operative bilateral 2D or 3D NA angles.The ICCs results showed that there were no consistency between the post-operative bilateral 2D or 3D NA angles （P values were 0.099 and 0.055, respectively）, but the excellent consistency between the 2D injured side NA angle and 2D IM nailing’ s NA angle, or between the 3D injured side NA angle and 3D IM nailing’s NA angle （the ICCs were 0.81 and 0.8, respectively, P values 〈0.001）.In PF-NA group, 57%of the differences between the 2D post-operative injured side’s and intact side’s NA an-gles were higher than 15°, which was more than 15.78%in InterTAN group.The paired student T-test showed no significant difference between the post-operative injured side’ s 2D or 3D NS angles and the in-tact side’s respective 2D or 3D angles in PFNA group （P values were 0.925 and 0.367, respectively）, but in InterTAN group, the post-operative injured side’s 2D or 3D NS angles were significantly smaller than the intact side’s respective angles （P values were 0.033 and 0.009, respectively）.Conclusion：By analyzing and comparing bilateral proximal femoral anatomical parameters after two kinds of IM nailings procedures, the differences between the bilateral post-operative NA angles in PFNA group were significantly larger than those in InterTAN group.There was significant correlation between the NA angles of the injured sides and NA angles of IM nailings in both the groups.