Massive rotator cuff tear associated with acute traumatic posterior shoulder dislocation: report of two cases and literature review

A massive rotator cuff tear in association with acute traumatic posterior glenohumeral dislocation is rare. To our knowledge, only four documented cases have been reported in the literature. We present two additional cases of such injury secondary to the traffic accident. The first patient had an unsuccessful closed reduction due to the posterior instability while the second developed the profound shoulder weakness following the reduction. From the findings of our cases together with the previous reports, every patient had a unique injury mechanism of high-energy directed axial loading on an outstretched, adducted, and internally rotated arm. The glenohumeral capsule and rotator cuff were uniformly avulsed from the humeral attachment, and the supraspinatus and infraspinatus were always involved. However, the clinical presentations were variable based on the severity of the associated rotator cuff tear. The outcomes of operative treatment in this type of injury with the open repair were favorable.