Étude IRM prospective sur l’influence de l’immobilisation en rotation externe sur la réduction et la cicatrisation des lésions capsulolabrales après une primoluxation de l’épaule

Abstract

IntroductionThe healing of the labral, capsular and glenohumeral ligament lesions represents the fundamental element to avoid recurrence of an anteromedial glenohumeral dislocation. The position of immobilization after a first anterior shoulder dislocation has been a controversial topic over the past decade. Few studies have demonstrated the superiority of the immobilization in external rotation position in the healing process. We have assessed through an MRI control, the effect of this immobilization on the labral, capsular and glenohumeral ligament injuries caused by the anteromedial dislocation of the shoulder. Patients and methodOur prospective study was carried on a duration of 1 year. Only patients with a primary anteromedial shoulder dislocation to sports subjects and having already accepted our protocol of stabilization in external rotation were included. Two MRIs was performed for each patient: immediately after reduction and 6 months later according to the same protocol: an acquisition in internal rotation (IR), followed by an acquisition in external rotation (ER). Hemarthrosis, rotator cuff, bone lesions, labral and capsular lesions were assessed and analyzed. ResultsWe selected 20 patients (19 men) with an average age of 24 years. Seventy-five percent of the dislocations were extracoracoid and 25% sub-coracoid. The reduction was done in the hospital after anteroposterior radiography of shoulder. All the patients were immobilized in an external rotation position using a thermoformable orthosis during 3 weeks followed by 6 weeks of rehabilitation. During the initial MRI: the hemarthrosis was almost constant; all separated labrums were reduced by external rotation including 10 completely. In all patients, the subscapularis was detached and totally reduced by external rotation in 60% of cases. After 6 months, the MRI showed that among the 18 patients with lesions labral, 15 have a complete healing without detachment and 3 patients had kept a residual detachment in internal rotation. The subscapularis was completely healed in 90% of cases. ConclusionThe immobilization in external rotation position allows a reduction of the hemarthrosis, the anterior capsular detachment and the labral lesions. Indeed, the immobilization in external rotation is constraining for the patient, yet the results seem encouraging.