Prevalence comparison of accompanying lesions between primary and recurrent anterior dislocation in the shoulder.

BACKGROUND: Many authors have reported the presence of intra-articular lesions after primary dislocation of the shoulder joint. However, few studies have focused on their prevalence or the differences in accompanying lesions between primary and recurrent dislocations of the shoulder joint.
PURPOSE: This study was undertaken to investigate and analyze accompanying lesions, including types of anteroinferior labrum injuries, using diagnostic arthroscopy and magnetic resonance arthrography (MRA) in 144 patients with traumatic anterior dislocation of the shoulder joint. STUDY
DESIGN: Cohort study; Level of evidence, 3.
METHODS: There were 33 patients with 33 dislocations in the primary dislocation group and 111 patients with 111 dislocations in the recurrent dislocation group. Preoperative magnetic resonance arthrography and diagnostic arthroscopy were performed on all patients.
RESULTS: In the primary dislocation group, 8 Bankart lesions, 9 free anterior labrum periosteal sleeve avulsion (ALPSA) lesions, 4 bony Bankart lesions, and 1 adhesive ALPSA lesion were observed. In the recurrent dislocation group, 68 Bankart lesions, 11 free ALPSA lesions, 13 bony Bankart lesions, 16 adhesive ALPSA lesions, and 1 glenoid articular rim disruption lesion were found. There were 22 (66.6%) and 109 (98.1%) patients with lesions in the anteroinferior labrum in the primary and recurrent groups, respectively. There was a statistically significant difference between the 2 groups (P = .002). Also, there was a significant difference between the 2 groups in the prevalence of the Hill-Sachs lesion and inverted pear-shaped glenoid lesion (P = .008/P = .047). Inverted pear-shaped glenoids were observed in 15 patients in the recurrent group. In 139 of 144 patients, surgical findings of accompanying lesions coincided with magnetic resonance arthrography findings (96.5%).
CONCLUSION: Various forms of anteroinferior labral lesions were seen in patients with traumatic anterior dislocation of shoulder. The recurrent dislocation group showed a significantly higher prevalence of anteroinferior labral lesions and bony lesions in comparison with the primary group. In our study, magnetic resonance arthrography was an accurate method to assess accompanying lesions in first-time and recurrent anterior dislocation of the shoulder, suggesting that this may be a useful tool for determining a treatment method.