Magnetic resonance imaging evaluation of capsulolabral tears after traumatic primary anterior shoulder dislocation. A prospective comparison with arthroscopy of 25 cases.

The purpose of our study was to evaluate the use of static magnetic resonance imaging (MRI) as a preoperative diagnostic tool in young patients with a traumatic primary anterior shoulder dislocation. Twenty-five patients who had acute primary traumatic anterior shoulder dislocation were examined with MRI and arthroscopy. The patients (18 male and 7 female) were between 16 and 39 years old (mean age, 27 years). They had no previous shoulder dislocations. The dislocations were confirmed radiographically. Examination with MRI and arthroscopy was performed within 10 days after the trauma. The MRI evaluation was performed before the arthroscopic examination, and the images were interpreted by an experienced magnetic resonance radiologist. No information from the MRI examination was available to the orthopedic surgeons before arthroscopy. The standard of reference for comparison was arthroscopy. Subacute MRI evaluation identified 15 labral tears, 12 Hill-Sachs lesions, 1 total rotator cuff lesion, 1 partial joint side rotator cuff lesion, and 1 partial rupture of the biceps tendon. Arthroscopic examination revealed 22 labral tears, 15 Hill-Sachs lesions, 1 total rotator cuff lesion, 1 partial joint side rotator cuff tear, 1 partial rupture of the biceps tendon, and 1 osseous Bankart lesion. Anterior capsulolabral tears and Hill-Sachs lesions appeared with a high incidence after acute anterior primary shoulder dislocation. Conventional MRI was only moderately reliable in the preoperative evaluation of labral tears and Hill-Sachs lesions, and it failed to give an accurate, differentiated preoperative diagnosis of the capsulolabral lesions.