冈上肌腱在肩关节外展时运动轨迹研究及临床意义探讨

The study of movement locus of the supraspinatus tendon as the humerus was abducted and its clinical implication

目的 :通过对冈上肌腱外展力臂和运动轨迹的研究 ,分析冈上肌腱炎的产生、肩袖损伤的成因。方法 :选用 10侧经福尔马林液固定的尸体肩关节标本 ,测定肱骨从 0°～ 180°作外展运动时 ,冈上肌腱力线位移以及冈上肌腱与肩峰之间的距离变化 ;并测定冈上肌的厚度和宽度 ;计算力臂值和运动轨迹。结果 :在上臂由内收位外展的过程中 ,随着外展角度的不断增加 ,冈上肌的位移变化幅度逐渐变小。冈上肌腱在止点处、按肌腹处和临界区的平均厚度分别为 0 .49,0 .48和 0 .3 5cm。冈上肌腱的平均宽度为 2 .41cm。冈上肌腱的运动轨迹方程为Y(距离 ) =2 .5 8-0 .19x(外展角度 )。结论 :在上臂外展的起始阶段冈上肌腱的力臂变化最大 ;在上臂上展 0°～ 60°过程中 ,冈上肌腱与肩峰之间的距离随外展角度的增大而减小。

Objectve: The objective of this study was to analyze the cause of supraspinatus tendenitis and rotator cuff lesion through measurement of the abduction moment arms and movement locus of the supraspinatus.Methods: The study was performed on 10 formalin-fixed cadaveric shoulder specimens.Supraspinatus tendon excursions was made as the humerus was abducted from 0°～180°; the distance between supraspinatus and acromion, and the thickness and width of supraspinatus tendon were measured.Then the abduction monent arms and movement locus of the tendon were calculated.Results: During the abduction of the humerus from 0°～180°, the excursion of supraspinatus significantly decreased. The moment arm of supraspinatus was the largest when the humerus abducted from 0° to 30°;and it was the smallest when the humerus abducted from 90° to 120°,the values being 16.64±1.80 mm and 5.56±1.09 mm, respectively. The thicknesses of supraspinatus tendon were 0.49 cm (at inserition area), 0.48 cm (at critical portion) and 0.35 cm (at bellycross-sectional area), respectively.The average width of supraspinatus tendon was 2.41 cm. The distance between supraspinatus and acromion decreased with the increase of the humerus abduction. The equation of the movement locus of supraspinatus tendon was: Y(distance)=2.58-0.19x(abduction degrees). Conclusion: The moment arm of the supraspinatus tedon is the largest at the initial parts of the abduction of the arm and the distance of the tendon to the acromion decrease as the arm is abducted with a distance of zero about 60 degrees of abduction.)