Blasier R B, Guldberg R E, Rothman E D
Orthopaedic Research Laboratories, Section of Orthopaedic Surgery, University of Michigan, Ann Arbor, Mich.
J Shoulder Elbow Surg. 1992 May;1(3):140-50. doi: 10.1016/1058-2746(92)90091-G. Epub 2009 Feb 25.
The purpose of this study was to quantify in a biomechanical model the contributions to shoulder joint stability that are made by tensions in the four tendons of the rotator cuff and by static resistance of defined portions of the capsular ligaments. A materials testing machine was used to directly determine anterior joint laxity by measurement of the force required to produce a standard anterior subluxation. Shoulders were tested in external or neutral humeral rotation. Data were analyzed by multiway analysis of variance with regression analysis. This model simulated tensions in the rotator cuff musculature by applying static loads at the tendon insertion sites acting along the anatomic lines of action. A load in any of the cuff tendons resulted in a measurable and statistically significant contribution to anterior joint stability. The contributions between different tendons were not significantly different and did not depend on the humeral rotation (neutral or external). In neutral humeral rotation the superior and middle glenohumeral ligaments together function equally with the inferior glenohumeral ligament as primary stabilizers against anterior humeral translation. The posterior capsule is a secondary stabilizer. The external rotation of the abducted humerus increases anterior stability by more than doubling the stability contribution from the inferior glenohumeral ligament. The stability contribution from the posterior capsule is larger in external rotation than in neutral rotation but is still of secondary magnitude. In external rotation the stability contribution of the anterior capsule, including the superior glenohumeral ligament and the middle glenohumeral ligament, becomes insignificant. The model presented here simulates the combined effect of two major sources of shoulder stability. This versatile model permits the direct measurement of the contributions to anterior shoulder stability that are made by tensions in the rotator cuff tendons and by static resistance of defined capsular zones. The use of multiple regression analysis-a standard statistical technique but one relatively new to the orthopaedic literature-permits quantitative determination of the contribution of each independent variable to the dependent variable, shoulder stability.
本研究的目的是在生物力学模型中量化肩袖四个肌腱的张力以及关节囊韧带特定部分的静态阻力对肩关节稳定性的贡献。使用材料试验机通过测量产生标准前向半脱位所需的力来直接确定前向关节松弛度。在肱骨外旋或中立位时对肩部进行测试。数据通过多因素方差分析和回归分析进行分析。该模型通过在沿着解剖作用线的肌腱附着部位施加静态负荷来模拟肩袖肌肉组织中的张力。任何一个肩袖肌腱中的负荷都会对前向关节稳定性产生可测量且具有统计学意义的贡献。不同肌腱之间的贡献没有显著差异，并且不依赖于肱骨旋转（中立位或外旋）。在肱骨中立位旋转时，肩肱上韧带和中韧带共同作为对抗肱骨前向平移的主要稳定器，其作用与肩胛下韧带相同。后关节囊是次要稳定器。外展肱骨的外旋使肩胛下韧带的稳定贡献增加一倍以上，从而使前向稳定性增加。后关节囊在肱骨外旋时的稳定贡献大于中立位旋转时，但仍然是次要的。在肱骨外旋时，包括肩肱上韧带和中韧带的前关节囊的稳定贡献变得微不足道。这里提出的模型模拟了肩关节稳定性两个主要来源的综合作用。这个通用模型允许直接测量肩袖肌腱的张力和特定关节囊区域的静态阻力对肩关节前向稳定性的贡献。使用多元回归分析——一种标准的统计技术，但在骨科文献中相对较新——可以定量确定每个自变量对因变量肩关节稳定性的贡献。
