Orthopaedic Biomechanics Laboratory, Division of Orthopaedic Surgery, University of Ottawa, Ottawa, ON, Canada.
J Shoulder Elbow Surg. 2010 Apr;19(3):406-13. doi: 10.1016/j.jse.2009.09.009. Epub 2009 Dec 11.
Our hypothesis was that tightening of the posterior capsule would lead to increased subacromial pressure and increased superior translation during active abduction in the scapular plane.
Subacromial impingement syndrome is a painful condition that occurs during overhead activities as the rotator cuff is compressed in the subacromial space. Unrecognized secondary causes of subacromial impingement may lead to treatment failure. Posterior capsular tightness, believed to alter glenohumeral joint kinematics, is often cited as a secondary cause of SI; however, scientific evidence is lacking. The primary objective of this study was to evaluate the effect of posterior capsular tightening on peak subacromial pressure during abduction in the scapular plane.
Ten fresh frozen shoulder specimens from deceased donors were mounted on a custom shoulder simulator. With the scapula fixed, the deltoid and rotator cuff muscles were loaded in discrete static steps with a constant ratio to elevate the humerus in the scapular plane. The treatment order (no tightening, 1-cm, and 2-cm tightening of the posterior capsule) was randomly assigned to each specimen. Peak subacromial contact pressure and glenohumeral kinematics at the peak pressure position were compared using a repeated measures analysis of variance.
Peak subacromial pressures (mean +/- standard deviation) were similar between treatment groups: 345 +/- 152, 410 +/- 213, and 330 +/- 164 kPa for no tightening, 1-cm, and 2-cm tightening of the posterior capsule respectively (P > .05). No significant differences were found for superior or anterior translations at the peak pressure position (P > .05).
Posterior capsular tightening, as a sole variable, did not contribute to a significant increase in peak subacromial pressure during abduction in the scapular plane. A similar study simulating active forward flexion is necessary to fully characterize the contribution of posterior capsular tightness to subacromial impingement.
Tightening of the posterior capsule did not increase subacromial pressure, or increase superior or anterior translation during abduction in the scapular plane.
我们的假设是，后囊的收紧会导致肩峰下压力增加，并在肩胛骨平面的主动外展中增加肩峰上移。
肩峰下撞击综合征是一种在过头活动中发生的疼痛病症，此时肩袖在肩峰下空间受到压缩。未被识别的肩峰下撞击的次要原因可能导致治疗失败。后囊紧绷被认为会改变盂肱关节运动学，常被认为是 SI 的次要原因；然而，缺乏科学证据。本研究的主要目的是评估肩胛骨平面外展时后囊收紧对肩峰下峰值压力的影响。
来自已故供体的 10 个新鲜冷冻肩部标本固定在定制的肩部模拟器上。肩胛骨固定后，三角肌和肩袖肌肉以恒定比例加载离散的静态步骤，以在肩胛骨平面中抬高肱骨。处理顺序（无收紧、后囊 1 厘米和 2 厘米收紧）随机分配给每个标本。使用重复测量方差分析比较峰值肩峰接触压力和峰值压力位置的盂肱关节运动学。
在无收紧、后囊 1 厘米和 2 厘米收紧的情况下，峰值肩峰压力（平均值±标准差）分别为 345±152、410±213 和 330±164kPa（P>.05），各组之间差异无统计学意义。在峰值压力位置，没有发现肩峰上移或前向移位的显著差异（P>.05）。
作为唯一变量，后囊收紧不会导致肩胛骨平面外展时肩峰下峰值压力显著增加。有必要进行类似的模拟主动前屈的研究，以充分描述后囊紧绷对肩峰下撞击的贡献。
后囊收紧不会增加肩胛骨平面外展时的肩峰下压力，也不会增加肩峰上移或前向移位。
