Department of Bioengineering, Swanson School of Engineering, Musculoskeletal Research Center, University of Pittsburgh, 408 Center for Bioengineering, 300 Technology Drive, Pittsburgh, Pennsylvania 15219, USA.
J Orthop Res. 2013 Jun;31(6):962-8. doi: 10.1002/jor.22300. Epub 2013 Jan 17.
During shoulder dislocation, the glenohumeral capsule undergoes non-recoverable strain, leading to joint instability. Clinicians use physical exams to diagnose injury and direct repair procedures; however, they are subjective and do not provide quantitative information. Our objectives were to: (1) determine the relationship between capsule function following anterior dislocation and non-recoverable strain; and (2) identify joint positions at which physical exams can be used to detect non-recoverable strain in specific capsule regions. Physical exams were simulated at three joint positions including external rotation (ER) using robotic technology before and after anterior dislocation. The resulting joint kinematics, strain distribution in the capsule, and non-recoverable strain were determined. Following dislocation, anterior translation increased by as much as 48% (0° ER: p = 0.03; 30° ER: p = 0.03; 60° ER: p < 0.01). Capsule sub-regions with less non-recoverable strain required more ER to detect differences in the strain ratios between the intact and injured joint. Strain ratio changes on the humeral side of the posterior axillary pouch (0.31 ± 0.32) were significant at all joint positions (0° ER: p = 0.03; 30° ER: p = 0.048; 60° ER: p = 0.04), whereas strain ratio differences on the humeral side of the anterior axillary pouch (0.18 ± 0.21) were significant only at 60° of ER (p = 0.03). Therefore, standardizing physical exams for joint position could help surgeons identify specific locations of non-recoverable strain that may have been ignored.
在肩关节脱位时，盂肱关节囊会发生不可恢复的拉伸，导致关节不稳定。临床医生使用体格检查来诊断损伤并指导修复程序；然而，这些检查具有主观性，且无法提供定量信息。我们的目的是：(1) 确定盂肱关节囊在前脱位后的功能与不可恢复拉伸之间的关系；(2) 确定在哪些关节位置可以使用体格检查来检测特定关节囊区域的不可恢复拉伸。使用机器人技术在三个关节位置（包括外旋位）模拟体格检查，分别为前脱位前和前脱位后。确定了关节运动学、关节囊内的应变分布和不可恢复拉伸的情况。前脱位后，前向平移增加了 48%（外旋 0°：p = 0.03；外旋 30°：p = 0.03；外旋 60°：p < 0.01）。不可恢复拉伸量较小的关节囊亚区需要更大的外旋角度才能检测到完整关节和损伤关节之间的应变比差异。后腋窝囊肱骨侧的应变比变化（0.31 ± 0.32）在所有关节位置（外旋 0°：p = 0.03；外旋 30°：p = 0.048；外旋 60°：p = 0.04）均有统计学意义，而前腋窝囊肱骨侧的应变比差异（0.18 ± 0.21）仅在外旋 60°时有统计学意义（p = 0.03）。因此，标准化体格检查的关节位置可能有助于外科医生识别可能被忽视的特定不可恢复拉伸部位。
