抄録
The purpose of this study was to evaluate MR arthrograms, recovery of shoulder muscle strength, and clinical results after immobilization in external rotation after initial traumatic shoulder dislocation and subluxation. Subjects were 6 patients who suffered initial traumatic shoulder dislocation or subluxation, and wore an external rotation immobilizer for 3 weeks from 2 days on the average after the onset. Then, active range of motion exercises restricted to 10 degrees external rotation and 90 degrees flexion and abduction was continued until 6 weeks after the onset. Return to sports was permitted at 4 months. MR arthrograms and muscle strength including flexion, abduction, and both external and internal rotation, were examined at 3 months after the onset. Recurrent dislocation or subluxation was evaluated for clinical results. 2 patients showed normal, and 4 patients showed labral detachment with displacement of Hirose's classification in MR arthrograms. The muscle strength showed no side-to-side differences in flexion, abduction and internal rotation. 1/2 of the cases had recurrence 1 year after the onset. All of them showed labral detachment in MR arthrograms. Return to sports at 4 months after the onset could be reasonable based on the results of recovery of muscle strength in this study. However, an obvious Bankart lesion in MR arthrogram 3 months after the onset might indicate a risk of recurrence. Further study for the protocol of conservative treatment using an external rotation immobilizer should be considered.
