Soslowsky L J, Flatow E L, Bigliani L U, Pawluk R J, Ateshian G A, Mow V C
Orthopaedic Research Laboratories, University of Michigan, Ann Arbor 48109-0486.
J Orthop Res. 1992 Jul;10(4):524-34. doi: 10.1002/jor.1100100407.
Glenohumeral arthritis may result from abnormal articular mechanics, and shoulder reconstructive procedures often rely implicitly on the belief that the restoration of normal articular mechanics is required to obtain satisfactory clinical results. Despite this, limited knowledge of normal or pathologic glenohumeral joint articular mechanics and contact is available. This study uses a stereophotogrammetry technique to determine contact areas in normal cadaver glenohumeral joints with intact ligaments and capsule through a large range of motion using simulated forces of the four rotator cuff muscles and three deltoid heads. All shoulders were first elevated to their maximum elevation in the scapular plane at an external rotation (starting rotation = 40 +/- 8 degrees), which allowed each shoulder to attain its maximal elevation in the scapular plane, and then repeated at 20 degrees internal to this rotation. Contact areas consistently increased with increasing elevation until 120 degrees to an average of 5.07 cm2 before decreasing with further increased elevation to an average of 2.59 cm2 at 180 degrees of total arm elevation. At 20 degrees internal to the starting rotation, contact areas reached high values 60 degrees earlier (averaged 4.56 cm2 at 60 degrees of total arm elevation) and then remained fairly constant through 120 degrees before decreasing with further increased elevation to 2.51 cm2 at 180 degrees total arm elevation. With increasing elevation in the external starting rotation, humeral head contact dramatically migrates from an inferior region to a superocentral-posterior region while glenoid contact shifts posteriorly. When the humeral shaft is positioned 20 degrees internal to the starting rotation, humeral head contact shifts from inferocentral-anterior to superocentral-posterior regions. Simultaneously, a similar posterior shift in glenoid contact is observed. Furthermore, whereas only a small portion of the humeral head surface area is in contact in any given position, contact on the glenoid surface is much more uniformly distributed over its entire articulating surface.
盂肱关节炎可能由异常的关节力学导致，而肩部重建手术常常隐含地依赖于这样一种信念，即恢复正常的关节力学是获得满意临床效果所必需的。尽管如此，关于正常或病理性盂肱关节的关节力学和接触情况的了解仍然有限。本研究使用立体摄影测量技术，通过模拟四块肩袖肌肉和三个三角肌头的力量，在完整韧带和关节囊的正常尸体盂肱关节中，在大范围运动中确定接触面积。所有肩部首先在肩胛平面以外部旋转（起始旋转 = 40 +/- 8度）提升至其最大高度，这使得每个肩部能够在肩胛平面达到其最大高度，然后在该旋转向内20度时重复该操作。接触面积随着高度增加持续增加，直到120度时平均达到5.07平方厘米，之后随着进一步升高到总手臂抬高180度时平均降至2.59平方厘米而减小。在起始旋转向内20度时，接触面积提前60度达到高值（总手臂抬高60度时平均为4.56平方厘米），然后在120度之前保持相当稳定，之后随着进一步升高到总手臂抬高180度时降至2.51平方厘米而减小。随着外部起始旋转中高度的增加，肱骨头接触显著地从下部区域迁移到上中央 - 后部区域，而肩胛盂接触向后移位。当肱骨干位于起始旋转向内20度时，肱骨头接触从下中央 - 前部转移到上中央 - 后部区域。同时，观察到肩胛盂接触有类似的向后移位。此外，尽管在任何给定位置只有一小部分肱骨头表面积处于接触状态，但肩胛盂表面的接触在其整个关节表面分布更为均匀。
