Wakabayashi Ikuko, Itoi Eiji, Sano Hirotaka, Shibuya Yotsugi, Sashi Ryuji, Minagawa Hiroshi, Kobayashi Moto
Department of Orthopedic Surgery, Akita University School of Medicine, Hondo, Japan.
J Shoulder Elbow Surg. 2003 Nov-Dec;12(6):612-7. doi: 10.1016/s1058-2746(03)00214-3.
We performed 2-dimensional finite element model analysis to estimate the mechanical environment of the supraspinatus tendon. The geometric shape of the finite element model was determined by magnetic resonance imaging of a normal human shoulder obtained at 0 degrees, 30 degrees, and 60 degrees of abduction, whereas the histologic location of noncalcified and calcified fibrocartilage was determined from a cadaveric specimen. The supraspinatus tendon was pulled proximally with the force of 10 N at 0 degrees, 53 N at 30 degrees, and 115 N at 60 degrees of abduction. The area of high principal stress maximum was observed on the articular side of the supraspinatus tendon, which shifted toward the insertion as the arm was abducted. High stress concentration on the articular side of the supraspinatus tendon near its insertion during arm elevation may explain the frequent occurrence of rotator cuff tears at this site.
我们进行了二维有限元模型分析，以评估冈上肌腱的力学环境。有限元模型的几何形状由在0度、30度和60度外展时获得的正常人体肩部磁共振成像确定，而非钙化和钙化纤维软骨的组织学位置则从尸体标本中确定。在0度外展时，以10 N的力向近端牵拉冈上肌腱；在30度外展时，以53 N的力牵拉；在60度外展时，以115 N的力牵拉。在冈上肌腱的关节侧观察到最大主应力高值区域，随着手臂外展，该区域向止点移动。手臂抬高时，冈上肌腱止点附近关节侧的高应力集中可能解释了该部位肩袖撕裂的频繁发生。
