Comparative Effectiveness of Different Immobilization Techniques in Managing Reduction of Acute Anterior Shoulder Dislocation: A Retrospective Cohort Study.

Purpose: The treatment of primary traumatic anterior shoulder dislocation varies widely. However, recent basic science and clinical data do not unify the specific immobilization methods. We aimed to compare the effectiveness of immobilization in internal rotation, external rotation and external rotation combined abduction after primary anterior dislocation of the shoulder. Methods: A total of 165 patients (80 males and 85 females, average age, 61 years, range 18-73 years) with the diagnosis of acute primary traumatic anterior shoulder dislocation were immobilized at in internal rotation (IR, n = 62), external rotation (ER, n = 53), external rotation combined abduction (ERAb, n = 50) after manipulative reduction. The mean follow-up period was 23.85 months (range 16-28 months). Patients received rehabilitation program immediately after immobilization. We assessed functionality by constant-Murley score (CMS), American Shoulder and Elbow Surgeons Scale (ASES) and stability by Western Ontario Shoulder Instability Index (WOSI) in week 6, months 3, 6, 12, and 24. Otherwise, the measured humeral upward distance (HUD) and humeral forward distance (HFD) on Computed Tomography (CT) of the shoulder were determined in day 1 and sixth weeks after immobilization. Results: for HUD and HFD, there were statistically significant differences between shoulder joint immobilization at 1 day and 6 weeks within each group (P < 0.001), and there were all significantly bigger than in the contralateral side on the day 1 of immobilization (P < 0.001), but after 6 weeks of shoulder joint immobilization, although slight differences existed between the affected and non-affected side in each group, none of these varieties reached significance (P > 0.05). Intragroup comparisons of the constant-Murley score (CMS), American Shoulder and Elbow Surgeons Scale (ASES) and Western Ontario Shoulder Instability Index (WOSI) in the different time periods revealed significant differences (P < 0.001). Furthermore, upon release of immobilization at the 6-week postoperative interval, the ERAb group demonstrated superior early phase mobility and functional recovery compared to the other two cohorts. However, longitudinal evaluation revealed no statistically significant differences in functional outcomes among the groups after the 3-month follow-up assessment. Conclusions: Internal rotation, external rotation, and external rotation combined abduction immobilization are effective methods for reducing postoperative complications of acute anterior shoulder dislocation and we recommend the external rotation combined abduction immobilization approach to promote early recovery of shoulder function.