Yoo Yon-Sik, Kim Jeehyoung, Im Wooyoung, Jeong Jeung Yeol
Camp 9 Orthopedic Clinic, Hwaseong, Republic of Korea.
Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Republic of Korea.
Orthop J Sports Med. 2021 Feb 24;9(2):2325967120982965. doi: 10.1177/2325967120982965. eCollection 2021 Feb.
Posterior shoulder instability (PSI) is a relatively uncommon condition that occurs in about 10% of patients with shoulder instability. PSI is usually associated with dislocations due to acute trauma and multidirectional instability, but it can also occur with or without recognizable recurrent microtrauma. The infrequency of atraumatic or microtraumatic PSI and the lack of a full understanding of the pathoanatomy and the knowledge of management can lead to misdiagnosis or delayed diagnosis.
To evaluate the morphologic factors of the glenoid that are associated with atraumatic or microtraumatic PSI.
Cross-sectional study; Level of evidence, 3.
Enrolled in this study were patients who underwent arthroscopic posterior labral repair between January 2013 and March 2017 and were diagnosed with posterior glenohumeral instability by means of preoperative computed tomography arthrography (CTA) (n = 39; PSI group). These patients did not have any significant dislocation or subluxation episodes. The morphologic factors of the glenoid as revealed using CTA were compared with the CTA images from a sex-matched control group (n = 117) of patients without PSI who had been diagnosed with adhesive capsulitis in an outpatient clinic. The glenoid version and shape were evaluated between the 2 groups using the CTA findings, and the degree of centricity of the humeral head to the glenoid was assessed in the PSI group. Multivariate logistic regression analysis was performed to identify factors associated with PSI.
The results of the multivariate logistic regression analysis indicated no statistically significant difference between the PSI and control groups regarding glenoid version or a flat-shaped glenoid. However, statistically significant between-group differences were found regarding convex glenoid shape, with an odds ratio of 5.39 (95% CI, 1.31-23.35; = .0207). The proportion of eccentricity was significantly higher in the PSI group (21/39; 54%) versus the control group (47/117; 40%) ( = .031).
The presence of convex glenoid shape was significantly associated with atraumatic or microtraumatic PSI. Humeral head eccentricity accounted for a high percentage of convex glenoid shape. However, there was no significant correlation between PSI and glenoid retroversion.
肩后不稳（PSI）是一种相对少见的病症，约占肩关节不稳患者的10%。PSI通常与急性创伤和多向不稳导致的脱位相关，但也可在有或无明显反复微创伤的情况下发生。非创伤性或微创伤性PSI的罕见性以及对病理解剖的全面理解和治疗知识的缺乏可能导致误诊或延迟诊断。
评估与非创伤性或微创伤性PSI相关的肩胛盂形态学因素。
横断面研究；证据等级，3级。
本研究纳入了2013年1月至2017年3月间接受关节镜下肩胛盂唇修复术且术前通过计算机断层扫描关节造影（CTA）诊断为肩肱关节后不稳的患者（n = 39；PSI组）。这些患者没有任何明显的脱位或半脱位发作。将使用CTA显示的肩胛盂形态学因素与来自门诊诊断为粘连性关节囊炎的无PSI的性别匹配对照组（n = 117）的CTA图像进行比较。使用CTA结果评估两组之间的肩胛盂版本和形状，并在PSI组中评估肱骨头相对于肩胛盂的中心度。进行多变量逻辑回归分析以确定与PSI相关的因素。
多变量逻辑回归分析结果表明，PSI组和对照组在肩胛盂版本或扁平形肩胛盂方面无统计学显著差异。然而，在凸形肩胛盂形状方面发现了组间统计学显著差异，优势比为5.39（95% CI，1.31 - 23.35；P = 0.0207）。PSI组的偏心比例（21/39；54%）显著高于对照组（47/117；40%）（P = 0.031）。
凸形肩胛盂形状的存在与非创伤性或微创伤性PSI显著相关。肱骨头偏心在凸形肩胛盂形状中占很高比例。然而，PSI与肩胛盂后倾之间无显著相关性。
