抄録
It is generally believed that the supraspinatus tendon plays an important role in the shoulder function. However, precise anatomy of the supraspinatus tendon has not been well described. The purpose of this study was to investigate the anatomy of the supraspinatus tendon. 57 cadavers (103 shoulders) were used for this study. The clavicle and humerus were cut off at their proximal parts. After resection of the acromion, the coracohumeral ligament was carefully removed. In some specimens, the infraspinatus was completely removed from the humerus to observe the overlapping portion of the supraspinatus and infraspinatus. The supraspinatus muscle and its origin were carefully investigated macroscopically. In 4 shoulders, muscle fibers were completely removed to examine the direction and insertion of the supraspinatus tendon in detail. The supraspinatus muscle fibers originated from the spine of the scapula and the supraspinatus fossa, and they were running toward and attached to the thickest tendinous portion, which was located at the anterior part of the supraspinatus muscle. This tendinous portion was strongly attached to the most anterior portion of the greater tuberosity adjacent to the bicipital groove or at the lesser tuberosity (21.3%). Another part of the supraspinatus, which was located posteriorly, was attached to the greater tuberosity adjacent to the articular cartilage as a thin membrane. The insertion of the supraspinatus tendon revealed to be the most anterior portion of the greater tuberosity and the lesser tuberosity. These results suggested that the supraspinatus tendon worked more efficiently as an abductor of the shoulder joint with the arm externally rotated than internal rotation.
