Wu Chenliang, Wang Yufan, Wang Cong, Chen Jiebo, Xu Junjie, Yu Wanxin, Huang Kai, Ye Zipeng, Jiang Jia, Tsai Tsung-Yuan, Zhao Jinzhong, Xie Guoming
Department of Sports Medicine, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China.
Am J Sports Med. 2022 Dec;50(14):3881-3888. doi: 10.1177/03635465221126650. Epub 2022 Oct 27.
The glenoid track concept has been widely used to assess the risk of instability due to bipolar bone loss. The glenoid track width was commonly used as 83% of the glenoid width to determine if a lesion was on-track or off-track. However, the value was obtained under static conditions, and it may not be able to reflect the actual mechanism of traumatic dislocation during motion.
To compare the glenoid track width under dynamic and static conditions using a dual-fluoroscopic imaging system.
Controlled laboratory study.
In total, 40 shoulders of 20 healthy volunteers were examined for both dynamic and static tests within a dual-fluoroscopic imaging system at 5 different arm positions: 30°, 60°, 90°, 120°, and 150° of abduction, keeping the shoulder at 90° of external rotation. The participants performed a fast horizontal arm backswing for dynamic tests while keeping their arm in maximum horizontal extension for static tests. Computed tomography scans were used to create 3-dimensional models of the humerus and scapula for 2-dimensional to 3-dimensional image registration. Magnetic resonance imaging scans were obtained to delineate the medial margin of the rotator cuff insertion. The glenoid track width was measured as the distance from the anterior rim of the glenoid to the medial margin of the rotator cuff insertion and compared between static and dynamic conditions.
The mean glenoid track widths at 30°, 60°, 90°, 120°, and 150° of abduction were significantly smaller under dynamic conditions (88%, 81%, 72%, 69%, and 68% of the glenoid width) than those under static conditions (101%, 92%, 84%, 78%, and 77% of the glenoid width) (all < .001). The glenoid track width significantly decreased with the increasing abduction angles in the range of 30° to 120° under static conditions (all < .003) and 30° to 90° under dynamic conditions (all < .001).
A smaller dynamic-based value should be considered for the glenoid track width when distinguishing on-track/off-track lesions. Clinical evidence is needed to establish the superiority of the dynamic-based value over the static-based value as an indicator for augmentation procedures.
Some off-track lesions might be misclassified as on-track lesions when the original commonly used static-based value of 83% is used as the glenoid track width.
肩胛盂轨迹概念已被广泛用于评估由于双极骨质流失导致的不稳定风险。肩胛盂轨迹宽度通常被用作肩胛盂宽度的83%，以确定病变是在轨迹上还是偏离轨迹。然而，该值是在静态条件下获得的，可能无法反映运动过程中创伤性脱位的实际机制。
使用双荧光透视成像系统比较动态和静态条件下的肩胛盂轨迹宽度。
对照实验室研究。
在双荧光透视成像系统中，对20名健康志愿者的40个肩部在5个不同的手臂位置进行动态和静态测试：外展30°、60°、90°、120°和150°，保持肩部外旋90°。参与者在动态测试中进行快速水平手臂后摆，而在静态测试中保持手臂最大水平伸展。使用计算机断层扫描创建肱骨和肩胛骨的三维模型，用于二维到三维图像配准。获得磁共振成像扫描以描绘肩袖插入的内侧边缘。肩胛盂轨迹宽度测量为从肩胛盂前缘到肩袖插入内侧边缘的距离，并在静态和动态条件下进行比较。
在外展30°、60°、90°、120°和150°时，动态条件下的平均肩胛盂轨迹宽度（分别为肩胛盂宽度的88%、81%、72%、69%和68%）显著小于静态条件下的（分别为肩胛盂宽度的101%、92%、84%、78%和77%）（均P <.001）。在静态条件下，肩胛盂轨迹宽度在30°至120°范围内随外展角度增加而显著减小（均P <.003），在动态条件下在30°至90°范围内显著减小（均P <.001）。
在区分轨迹上/轨迹外病变时应考虑基于动态的较小肩胛盂轨迹宽度值。需要临床证据来确立基于动态的值优于基于静态的值作为增强手术指标的优势。
当使用最初常用的基于静态的83%的值作为肩胛盂轨迹宽度时，一些轨迹外病变可能会被误分类为轨迹上病变。
