多层螺旋CT二维法测量肱骨头扭转角探讨

Study on the two-dimension method measuring the humeral head retroversion angle with multi-slice spiral CT

目的:探讨肱骨头扭转角多层螺旋CT二维测量方法,着重讨论肱骨头扭转角远端定义线对测值的影响。方法:收集51根肱骨干标本,行16层螺旋CT扫描,肱骨头中轴线与肱骨远端前关节面的切线,或内外上髁连线的夹角为肱骨头扭转角。肱骨远端定义线取上中下三个不同平面得到六组肱骨头扭转角度数,进行统计学处理。结果:肱骨头扭转角最小值4°,最大值59.8°,六组肱骨头扭转角数据分别为:(27.9±11.9)°、(29.2±11.2)°、(30.2±10.7)°、(27.3±10.3)°、(26.3±10.2)°、(25.8±10.4)°,经统计学处理,以肱骨远端前关节面切线为远端定义线测得肱骨头扭转角度数越往远端越大;而以肱骨内外上髁连线为远端定义线测得的值越往远端越小;肱骨远端下方层面两种定义线测得肱骨头扭转角有显著性差异,其余层面所得值无差异,上部层面两种定义线肱骨扭转角均数最为接近,相差仅0.6°。结论:肱骨头扭转角变异较大,肩关节假体扭转角设计应个性化;多层螺旋CT二维法测量肱骨头扭转角应取鹰嘴窝较深且显示肱骨远端前关节面清楚的层面做为远端定义层面。

Objective： To investigate the two-dimension method measuring the humeral head retroversion angle with multi-slice spiral CT and emphasize on discuss humeral head retroversion angle distal reference axis effect on measure value. Methods51 dry humerus specimens were scanned with 16-slice spiral CT scanner. The humeral head retroversion angle was defined as the angle between the humeral head central axis and a line between the epicondyles or between the humeral head central axis and the tangent to the anterior surface of the distal humerus articulation with the forearm. The distal reference axis of the humeral head retroversion angle was defined by three different levels, the total six-group data on humeral head retroversion angle were analyzed by Statistics. Results The humeral head retroversion angle ranged from 4° to 59.8° , the humeral head retroversion angle of six groups were （27.9±11.9）° , （29.2±11.2）°,（30.2±10.7）° ,（27.3±10.3 ）° , （26.3±10.2）°,（25.8± 10.4）° respectively. The Statistics showed that there was bigger the humeral head retroversion angle defined by the tangent to the anterior surface of the distal humerus articulation with the forearm, the more distal end of humerus; on the contrary, There was the smaller humeral head retroversion angle defined by a line between the epicondyles, the more distal humerus. The humeral head retroversion angle defined by two reference axis of the distal humerus of inferior level had significant difference, there was not significant difference on the humeral head retroversion angle defined by the other two levels. Above them, the mean of the humeral head retrovcrsion angle of superior level defined by the other two methods was near. The difference value was 0.6°. Conclusions： The humeral head retroversion angle is markedly variable, the design of humeral head retroversion angle of shoulder prosthesis should be individual. The reference section of the distal humerus for two-dimension method measuring the humeral head retroversion angle with multi-slice spiral CT shows the dceper olecranoid fossa and distinct anterior surface of the distal humerus.