Effectiveness of external rotation immobilization in highly active young men with traumatic primary anterior shoulder dislocation or subluxation.

We treated 15 highly active young men (16 shoulders) with traumatic primary anterior shoulder dislocation or subluxation using 3-week external rotation immobilization. Fourteen patients (14 shoulders) were members of the Self-Defense Force and the other patient (2 shoulders) was a high school student who played club-level rugby. Average patient age at the time of the primary injury was 21.3 years (range, 17-26 years). Magnetic resonance imaging (MRI) was performed on 14 of 16 shoulders after the 3-week external rotation immobilization and showed that the anteroinferior labrum was reduced on the glenoid rim in 11 shoulders but remained medially displaced on the glenoid neck in 3 shoulders. Five shoulders, including these 3 shoulders, underwent arthroscopic Bankart repair after 3-week external rotation immobilization. Eleven shoulders continued nonoperative treatment after the immobilization. Four of 11 shoulders had no recurrence of symptoms for >2 years, and these patients were able to return to their preinjury activities. However, 7 shoulders experienced recurrence within 2 years. We concluded that external rotation immobilization may not be as effective as mentioned previously in highly active young men with primary traumatic anterior shoulder dislocation or subluxation. Whether a patient has instability symptom recurrence after external rotation immobilization depends on more than the fact that the anteroinferior labrum is not reduced on MRI.