三维螺旋CT重建股骨远端旋转力线的测量

Measurement of the rotational alignment of the distal femur with 3-dimensional CT

目的:通过三维螺旋CT重建正常成人膝关节,测量股骨远端旋转力线,为全膝关节置换术股骨假体旋转力线的定位提供理论依据。方法:80侧正常成人膝关节,男性、女性各40侧,年龄18～72岁,行三维螺旋CT扫描,在GE Advantage workstation工作站上进行0.625mm层厚重建,测量股骨外科上髁轴线与股骨后髁轴线之间的夹角(股骨后髁角,PCA)及前后轴线的垂线与股骨后髁轴线的夹角(APA),比较男、女性股骨旋转力线的差异。结果:PCA:男性3.21°±1.35°(1.15°～5.92°),女性3.60°±1.40°(0.84°～5.76°);APA:男性3.17°±1.62°(0.87°～5.73°),女性3.66°±1.58°(1.34°～6.05°)。PCA与APA的差异无统计学意义,但性别间PCA及APA差异均有统计学意义,同时PCA和APA均有较大的个体差异。结论:男女性及不同个体之间股骨后髁角值存在一定差别,统一参照股骨后髁轴截骨将导致假体安放不准确,应采用多种定位方法确定股骨侧截骨,术前三维螺旋CT扫描重建股骨远端,测量后髁角,有利于术中重建准确的旋转力线。

Objective： In order to provide theoretical basis for the position of rotational alignment of the distal femur in the total knee arthroplasty. We measured the rotational alignment of the distal femur and reconstructed the knees of healthy adults in 3-dimensional spinal CT. Methods： Eighty knees of healthy Chinese adults （male 40, female 40; age： 18-72 years） were scanned by 3-dimensinal spinal CT and being reconstructed on the GE Advantage workstation with the 0.625mm-gap layer thick. The included angle （APA） between the perpendicular line of anteroposterior line （APL） and the posterior condylar line （PCL）, together with the posterior condylar angles （PCA） between STEA and PCL were measured to compare the difference between male and female. Results： PCA： male 3.21 °± 1.35 ° （1.15°～5.92°）, female 3.60°± 1.40° （0.84°～5.76°）; APA： male 3.17°± 1.62° （0.87°～5.73 °）, female 3.66°± 1.58° （1.34°～6.05°）. There was no statistics meaning on the difference between PCA and APA, but the PCA and APA difference between male and female had statistics meanings with relatively great variaties. Conclusion： There are certain individual and sexual variations on PCA. Because it is not accurate to incise all the bone according to the posterior condylar line,resulting in the improper position of false body, Different location methods should be applied on the determination of incision of femuro It would be helpful to accurately reconstruct the rotation alignment during the operation by using the 3-D dimensional spinal CT to scan and rebuild distal femur and measure PCA before the operation.