Immobilizatio in External Rotation for Initial Anterior Dislocation of the Glenohumeral Joint

Abstract

We verified the coaptaion effect of the subscapuraris muscle when the shoulder was immobilized the external rotation after initial anterior dislocation of the glenohumeral joint, and the practical use of the immobilizer to keep the shoulder in external rotation position. We evaluated twelve shoulders of the 12 patients with traumatic initial anterior dislocation of the shoulder. All of the patients were male, and the in mean age was 22.2 years old(range,17 to 30). Fast-spin-echo T2-weighted axial and sagittal magnetic resonance images were made, with the arm held at the side and positioned first in the maximum internal rotation and then in 15°external rotation within one week after the dislocation. We examined the coaptaion effect of the subscapuralis muscle comparing the images in the both positions. The patients were asked about the compliance and the discomfort of immobilization. Bankart lesions were identified in 11/12 shoulders (91.6%). The coaptaion effect was observed in 10/12shoulders (83.3%). All of the patients put on immobilizers for 3 weeks, and answered that discomfort was within the bounds of their torelance. Better coaptaion of a Bankart lesion was observed in external rotation compared with that in internal rotation. The immobilizer was of practical use.