Abstract：
BACKGROUND: Subacromial impingement syndrome is one of the most common causes of painful shoulder in the middle-aged and elderly population. Coracoacromial ligament (CAL) degeneration is a well-known indicator for subacromial impingement.
OBJECTIVE: To examine the relationship between CAL thickness on preoperative magnetic resonance imaging (MRI), arthroscopic CAL degeneration and types of rotator cuff tears.
METHODS: Video records of patients who underwent arthroscopic shoulder surgery between 2015 and 2021 were retrospectively scanned through the hospital information record system. In total, 560 patients were included in this study. Video records of the surgery were used to evaluate the grade of coracoacromial ligament degeneration and the type of cuff tear. Preoperative MRI was used to measure CAL thickness, acromiohumeral distance, critical shoulder angle, acromial index, and acromion angulation.
RESULTS: Significant differences were observed between grades of CAL degeneration in terms of CAL thickness (P < 0.001). As CAL degeneration increases, the mean of CAL thickness decreases. According to the results of post-hoc analysis, the mean CAL thickness of normal patients was significantly higher than those of patients with full-thickness tears (P = 0.024) and massive tears (P <0.001). Patients with articular-side, bursal-side, and full-thickness tears had significantly higher CAL thickness averages than patients with massive tears.
CONCLUSIONS: This study showed that the CAL thickness decreases on MRI as arthroscopic CAL degeneration increases. High-grade CAL degeneration and therefore subacromial impingement syndrome can be predicted by looking at the CAL thickness in MRI, which is a non-invasive method.
OBJECTIVE: To examine the relationship between CAL thickness on preoperative magnetic resonance imaging (MRI), arthroscopic CAL degeneration and types of rotator cuff tears.
METHODS: Video records of patients who underwent arthroscopic shoulder surgery between 2015 and 2021 were retrospectively scanned through the hospital information record system. In total, 560 patients were included in this study. Video records of the surgery were used to evaluate the grade of coracoacromial ligament degeneration and the type of cuff tear. Preoperative MRI was used to measure CAL thickness, acromiohumeral distance, critical shoulder angle, acromial index, and acromion angulation.
RESULTS: Significant differences were observed between grades of CAL degeneration in terms of CAL thickness (P < 0.001). As CAL degeneration increases, the mean of CAL thickness decreases. According to the results of post-hoc analysis, the mean CAL thickness of normal patients was significantly higher than those of patients with full-thickness tears (P = 0.024) and massive tears (P <0.001). Patients with articular-side, bursal-side, and full-thickness tears had significantly higher CAL thickness averages than patients with massive tears.
CONCLUSIONS: This study showed that the CAL thickness decreases on MRI as arthroscopic CAL degeneration increases. High-grade CAL degeneration and therefore subacromial impingement syndrome can be predicted by looking at the CAL thickness in MRI, which is a non-invasive method.
摘要：
背景：肩峰下撞击综合征是中老年人肩痛的最常见原因之一。喙肩峰韧带（CAL）变性是肩峰下撞击的众所周知的指标。
目的：为了检查术前磁共振成像（MRI）的CAL厚度之间的关系，关节镜下CAL变性和肩袖撕裂的类型。
方法：通过医院信息记录系统对2015年至2021年接受肩关节镜手术患者的视频记录进行回顾性扫描。总的来说,560名患者被纳入本研究。手术的视频记录用于评估喙肩峰韧带变性的等级和袖带撕裂的类型。术前MRI测量CAL厚度,肩关节距离,临界肩角,肩峰指数,和肩峰角度。
结果：在CAL厚度方面，CAL变性等级之间存在显著差异（P<0.001）。随着CAL变性的增加，CAL厚度的平均值减小。根据事后分析的结果，正常患者的平均CAL厚度明显高于全层撕裂（P=0.024）和大量撕裂（P<0.001）患者。患者关节侧，法氏囊一侧,全层泪液的CAL厚度平均值明显高于大量泪液患者。
结论：这项研究表明，随着关节镜下CAL变性的增加，MRI上CAL厚度减小。可以通过观察MRI中的CAL厚度来预测高度CAL变性和肩峰下撞击综合征，这是一种非侵入性的方法。
目的：为了检查术前磁共振成像（MRI）的CAL厚度之间的关系，关节镜下CAL变性和肩袖撕裂的类型。
方法：通过医院信息记录系统对2015年至2021年接受肩关节镜手术患者的视频记录进行回顾性扫描。总的来说,560名患者被纳入本研究。手术的视频记录用于评估喙肩峰韧带变性的等级和袖带撕裂的类型。术前MRI测量CAL厚度,肩关节距离,临界肩角,肩峰指数,和肩峰角度。
结果：在CAL厚度方面，CAL变性等级之间存在显著差异（P<0.001）。随着CAL变性的增加，CAL厚度的平均值减小。根据事后分析的结果，正常患者的平均CAL厚度明显高于全层撕裂（P=0.024）和大量撕裂（P<0.001）患者。患者关节侧，法氏囊一侧,全层泪液的CAL厚度平均值明显高于大量泪液患者。
结论：这项研究表明，随着关节镜下CAL变性的增加，MRI上CAL厚度减小。可以通过观察MRI中的CAL厚度来预测高度CAL变性和肩峰下撞击综合征，这是一种非侵入性的方法。
