Objective

The purpose of this study is to evaluate the accuracy of MR arthrography in detecting isolated posterior glenoid labral injuries using arthroscopy as the reference standard.

Methods

MR arthrograms of 97 patients with isolated posterior glenoid labral tears by arthroscopy and those of 96 age and gender-matched controls with intact posterior labra were reviewed by two blinded radiologists for the presence and location of posterior labral abnormalities. The sensitivity and specificity of detection of posterior labral tears were calculated as well as the prevalence of associated pathologies. Medical records were reviewed for demographics, history and direction of shoulder instability, and prior surgery.

Results

Posterior labral pathology was detected by MR arthrography with sensitivities of 76% and 84% for readers 1 and 2, and a specificity of 88% for both readers. Kappa value for interreader agreement was 0.91. Twenty-two of twenty-three (96%) tears isolated to the posteroinferior quadrant on arthroscopy were correctly identified on MRI. Commonly associated pathologies included paralabral cyst (38%), humeral fracture (7%), and glenoid fracture (2%). Fifteen of ninety-seven (16%) patients with posterior tears on both arthroscopy and MRI had glenoid rim deficiency on imaging versus no patients with intact posterior labra (p < 0.001). Forty of ninety-seven (41%) patients with posterior tears on arthroscopy had a history of posterior instability versus none without posterior tears. There was no significant difference in tear length on MRI between those with a history of instability and those without (p = 0.56).

Conclusion

MR arthrography is accurate in detecting posterior glenoid labroligamentous injuries.

中文翻译：

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MR 关节造影检测肩关节后盂唇损伤的准确性

客观的

本研究的目的是以关节镜作为参考标准，评估 MR 关节造影检测孤立性后关节盂唇损伤的准确性。

方法

两位采用盲法的放射科医师对 97 名通过关节镜检查发现后盂唇撕裂的患者和 96 名年龄和性别匹配且后盂唇完整的对照组的 MR 关节造影进行了检查，以确定后盂唇异常的存在和位置。计算了检测盂唇后部撕裂的敏感性和特异性以及相关病理学的患病率。回顾了医疗记录的人口统计资料、肩关节不稳的病史和方向以及既往手术史。

结果

通过 MR 关节造影检测盂唇后部病变，对读者 1 和读者 2 的敏感性分别为 76% 和 84%，对两位读者的特异性均为 88%。读者间一致性的 Kappa 值为 0.91。在关节镜检查中分离到后下象限的二十三个 (96%) 眼泪中的二十二个在 MRI 上被正确识别。常见的相关病理包括唇旁囊肿 (38%)、肱骨骨折 (7%) 和关节盂骨折 (2%)。九十七 (16%) 例关节镜检查和 MRI 均有后撕裂的患者中有十五例在影像学上有关节盂边缘缺损，而后盂唇完整的患者则没有（p < 0.001)。九十七名 (41%) 关节镜检查发现后部撕裂的患者中有 40 名有后部不稳定病史，而没有后部撕裂的患者则没有。有不稳定病史的患者和没有不稳定病史的患者在 MRI 上的撕裂长度没有显着差异 ( p  = 0.56)。

结论

MR 关节造影可准确检测后关节盂唇韧带损伤。