Thompson W O, Debski R E, Boardman N D, Taskiran E, Warner J J, Fu F H, Woo S L
Department of Orthopaedic Surgery, University of Pittsburgh, Pennsylvania, USA.
Am J Sports Med. 1996 May-Jun;24(3):286-92. doi: 10.1177/036354659602400307.
We conducted this cadaveric study to define a biomechanical rationale for rotator cuff function in several deficiency states. A dynamic shoulder testing apparatus was used to examine change in middle deltoid muscle force and humeral translation associated with simulated rotator cuff tendon paralyses and various sizes of rotator cuff tears. Supraspinatus paralysis resulted in a significant increase (101%) in the middle deltoid force required to initiate abduction. This increase diminished to only 12% for full glenohumeral abduction. The glenohumeral joint maintained ball-and-socket kinematics during glenohumeral abduction in the scapular plane with an intact rotator cuff. No significant alterations in humeral translation occurred with a simulated supraspinatus paralysis, nor with 1-, 3-, and 5-cm rotator cuff tears, provided the infraspinatus tendon was functional. Global tears resulted in an inability to elevate beyond 25 degrees of glenohumeral abduction despite a threefold increase in middle deltoid force. These results validated the importance of the supraspinatus tendon during the initiation of abduction. Glenohumeral joint motion was not affected when the "transverse force couple" (subscapularis, infraspinatus, and teres minor tendons) remained intact. Significant changes in glenohumeral joint motion occurred only if paralysis or anatomic deficiency violated this force couple. Finally, this model confirmed that rotator cuff disease treatment must address function in addition to anatomy.
我们开展了这项尸体研究，以确定肩袖在几种缺损状态下发挥功能的生物力学原理。使用动态肩部测试装置，来检测与模拟的肩袖肌腱麻痹及各种大小的肩袖撕裂相关的三角肌中部肌力和肱骨平移的变化。冈上肌麻痹导致外展起始时所需的三角肌中部肌力显著增加（101%）。对于全肩关节外展，这种增加仅降至12%。在肩胛平面进行肩关节外展时，若肩袖完整，肩关节保持球窝运动学特征。模拟冈上肌麻痹以及1厘米、3厘米和5厘米的肩袖撕裂，只要冈下肌腱功能正常，肱骨平移就不会发生显著改变。全层撕裂导致尽管三角肌中部肌力增加了两倍，但肩关节外展仍无法超过25度。这些结果证实了冈上肌腱在起始外展时的重要性。当“横向力偶”（肩胛下肌、冈下肌和小圆肌腱）保持完整时，肩关节运动不受影响。只有当麻痹或解剖缺损破坏了这个力偶时，肩关节运动才会发生显著变化。最后，该模型证实，肩袖疾病的治疗除了解剖结构外，还必须关注功能。
