Kim Seung-Ho, Noh Kyu-Chul, Park Jun-Sic, Ryu Byung-Dam, Oh Irvin
Department of Orthopaedic Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, 50 Ilwon-Dong, Kangnam-Ku, Seoul, Korea 135-710.
J Bone Joint Surg Am. 2005 Jan;87(1):92-8. doi: 10.2106/JBJS.C.01448.
Although the cause of posteroinferior instability of the shoulder has not been fully defined, glenoid version can be more completely measured when chondrolabral structures are included because conformity and containment of the glenohumeral joint are integral functions of both the articular cartilage and the labrum. The purpose of this study was to use magnetic resonance imaging-arthrography to evaluate the chondrolabral containment of the glenohumeral joint in patients with atraumatic posteroinferior multidirectional instability of the shoulder.
We evaluated four measurements (osseous and chondrolabral glenoid version, labral height, and glenoid depth) on T2-weighted axial magnetic resonance-arthrography images of thirty-three shoulders with atraumatic posteroinferior multidirectional instability. Shoulders with a documented labral tear were excluded. The measurements were compared with those of thirty-three age-matched controls without glenohumeral pathology. The angles of version of the osseous and chondrolabral portions of the glenoid were measured in three consecutive planes (superior 25%, middle 50%, and inferior 75% in relation to the superior lip of the glenoid) perpendicular to the long axis of the glenoid.
The shoulders with posteroinferior instability had greater retroversion of both the osseous and the chondrolabral portion of the glenoid in the middle and inferior planes. The chondrolabral portion of the glenoid had more retroversion than the osseous portion in the inferior plane. The height of the posterior portion of the labrum was decreased in the inferior plane in the shoulders with instability. Glenoid depth in the middle and inferior planes was significantly shallower in the shoulders with instability.
Loss of containment in the chondrolabral portion of the glenoid in the middle and inferior planes is a consistent finding in shoulders with atraumatic posteroinferior multidirectional instability and is associated with loss of posterior labral height. It is unclear whether the retroversion of the posteroinferior aspect of the labrum is a cause or a consequence of atraumatic posteroinferior multidirectional instability, but this factor should be considered during surgical repair.
尽管肩关节后下不稳定的病因尚未完全明确，但当包含软骨盂唇结构时，关节盂形态可以得到更全面的测量，因为盂肱关节的匹配性和包容性是关节软骨和盂唇的整体功能。本研究的目的是使用磁共振关节造影来评估非创伤性肩关节后下多向不稳定患者盂肱关节的软骨盂唇包容性。
我们在33例非创伤性肩关节后下多向不稳定患者的T2加权轴向磁共振关节造影图像上评估了四项测量指标（骨性和软骨盂唇关节盂形态、盂唇高度和关节盂深度）。排除有盂唇撕裂记录的肩关节。将这些测量结果与33例无盂肱关节病变的年龄匹配对照者的测量结果进行比较。在垂直于关节盂长轴的三个连续平面（相对于关节盂上唇的上25%、中50%和下75%）测量关节盂骨性和软骨盂唇部分的形态角度。
后下不稳定的肩关节在中平面和下平面的关节盂骨性和软骨盂唇部分均有更大的后倾。在关节盂下平面，软骨盂唇部分比骨性部分有更多的后倾。不稳定肩关节下平面的盂唇后部高度降低。不稳定肩关节中平面和下平面的关节盂深度明显更浅。
在非创伤性肩关节后下多向不稳定的肩关节中，中平面和下平面的关节盂软骨盂唇部分包容性丧失是一个一致的发现，并且与盂唇后部高度丧失有关。尚不清楚盂唇后下部分的后倾是非创伤性肩关节后下多向不稳定的原因还是结果，但在手术修复时应考虑这一因素。
