Lazarus M D, Sidles J A, Harryman D T, Matsen F A
Department of Orthopaedic Surgery, University of Washington Medical Center, Seattle 98195, USA.
J Bone Joint Surg Am. 1996 Jan;78(1):94-102. doi: 10.2106/00004623-199601000-00013.
One of the primary stabilizing mechanisms of the glenohumeral joint is concavity-compression, the maintenance of the humeral head in the concave glenoid fossa by the compressive force generated by the surrounding muscles. This mechanism is active in all glenohumeral positions but it is particularly important in the functional mid-range, in which the capsule and ligaments are slack. The effectiveness of concavity-compression in the stabilization of a joint can be characterized in terms of the ratio between the maximum dislocating force that can be stabilized in a given direction and the load compressing the head into the glenoid (the stability ratio). Glenoid concavity can be described by the lateral humeral displacement during translation across the glenoid. The purpose of the present investigation was to characterize the concavity and stability ratios of normal cadaveric glenoids, to measure the effect of an anteroinferior chondral-labral defect on these parameters, and to measure the effectiveness of a simulated operative reconstruction on the restoration of glenoid concavity and the stability ratio. The chondral-labral defect created in this study reduced the height of the glenoid by approximately 80 per cent and the stability ratio by approximately 65 per cent for translation in the direction of the defect. Reconstruction of the anteroinferior aspect of the glenoid concavity with use of an autogenous biceps-tendon graft restored normal values for these variables.
盂肱关节的主要稳定机制之一是凹面压缩，即通过周围肌肉产生的压缩力将肱骨头维持在凹陷的关节盂窝内。这种机制在盂肱关节的所有位置都起作用，但在功能中间范围内尤为重要，因为在此范围内关节囊和韧带是松弛的。凹面压缩在关节稳定中的有效性可以通过在给定方向上能够稳定的最大脱位力与将肱骨头压入关节盂的负荷之间的比率（稳定率）来表征。关节盂凹面可以通过肱骨头在关节盂上平移时的外侧移位来描述。本研究的目的是表征正常尸体关节盂的凹面和稳定率，测量前下软骨-盂唇缺损对这些参数的影响，并测量模拟手术重建对恢复关节盂凹面和稳定率的有效性。本研究中创建的软骨-盂唇缺损使关节盂高度降低了约80%，在缺损方向平移时稳定率降低了约65%。使用自体肱二头肌肌腱移植修复关节盂凹面的前下部分，使这些变量恢复到正常值。
