Posterior Instability of the Shoulder

Abstract

Recurrent posterior instability of the shoulder can be difficult to diagnose and technically challenging to treat. Although not as common as anterior instability, recurrent posterior shoulder instability is prevalent among certain demographic and sporting groups, and may be overlooked if one is not aware of the typical examination and radiographic findings. The diagnosis itself can be difficult as patients typically present with vague or confusing symptoms, and treatment has evolved from open to arthroscopic surgical techniques. This article is intended to review the anatomy and biomechanics associated with posterior shoulder instability, to discuss the pathogenesis and presentation of posterior instability, and to describe the variety of treatment options and clinical results.

Management of recurrent shoulder instability in patients with epilepsy

“…Plain radiographs in posterior instability are often normal, but axillary views can highlight a reverse Hill-Sachs lesion, posterior glenoid rim defects, and increased glenoid retroversion. 52 To enhance visualization of the glenoid, specialized projections (the Garth view provides a coronal profile of the glenohumeral joint; the Bernageau view reveals the anteroinferior aspect of the glenoid in patients with anterior instability) can be useful. 5,21 Loss of the anterior sclerotic line of the glenoid on anteroposterior radiographs has been identified as a moderately sensitive finding for anterior glenoid rim defects.…”

“…44,64 This has been attributed to the more extensive surgical approach required to visualize the posterior structures, the inability to identify all the associated pathologic lesions, and the limited capacity of a posteriorly situated bone block to restore stability. 52,69 In the presence of bone loss, though, posterior bone block procedures effectively treat instability and improve functional outcome. 3,62 …”

Posterior Shoulder Instability in Athletes

“…Such lesions are usually located along the anterior and superomedial portions of the humeral head and may be associated with extensive anterior cartilaginous damage 39 . The lesion may articulate with the glenoid when the humerus is in a position of flexion, adduction, and internal rotation 40 .…”

Posterior Bone Grafting for Glenoid Defects of the Shoulder

“…The PIGHL serves the most important function in a position of posterior loading of the shoulder and prevents posteroinferior movement of the humeral head during internal rotation and forward flexion of the humerus. 68 …”