The glenohumeral joint with instability is a common diagnosis that often requires surgery. The aim of this review was to present an overview of the anatomy of the glenohumeral joint with emphasis on instability based on the current literature and to describe the detailed anatomy and anatomical variants of the glenohumeral joint associated with anterior and posterior shoulder instability. A review was performed using PubMed/MEDLINE using key words: Search terms were "glenohumeral", "shoulder instability", "cadaver", "rotator interval", "anatomy", and "anatomical study". During the last decade, the interest in both arthroscopic repair techniques and surgical anatomy of the glenohumeral ligament (superior, middle, and inferior), labrum, and rotator interval has increased. Understanding of the rotator interval and attachment of the inferior glenohumeral ligament on the glenoid or humeral head have evolved significantly. The knowledge of the detailed anatomy and anatomical variations is essential for the surgeon in order to understand the pathology, make a correct diagnosis of instability, and select proper treatment options. Proper understanding of anatomical variants can help us avoid misdiagnosis. Level of evidence V.

BACKGROUND:Only a few reports describe the extension of the coracohumeral ligament to the subscapularis muscle. The purposes of this study were to histo-anatomically examine the structure between the ligament and subscapularis and to discuss the function of the ligament. METHODS:Nineteen intact embalmed shoulders were used. In 9 shoulders, the expansion of the ligament was anatomically observed, and in 6 of these 9, the muscular tissue of the supraspinatus and subscapularis was removed to carefully examine the attachments to the tendons of these muscles. Five shoulders were frozen and sagittally sectioned into 3-mm-thick slices. After observation, histologic analysis was performed on 3 of these shoulders. In the remaining 5 shoulders, the coracoid process was harvested to investigate the ligament origin. RESULTS:The coracohumeral ligament originated from the horizontal limb and base of the coracoid process and enveloped the cranial part of the subscapularis muscle. The superficial layer of the ligament covered a broad area of the anterior surface of the muscle. Laterally, it protruded between the long head of the biceps tendon and subscapularis and attached to the tendinous floor, which extended from the subscapularis insertion. Histologically, the ligament consisted of irregular and sparse fibers abundant in type III collagen. CONCLUSION:The coracohumeral ligament envelops the whole subscapularis muscle and insertion and seems to function as a kind of holder for the subscapularis and supraspinatus muscles. The ligament is composed of irregular and sparse fibers and contains relatively rich type III collagen, which would suggest flexibility.

Recurrent anterior shoulder dislocation is always combined with glenoid and capsule-labrum deficiency. To address all these deficiency in a single operation, we developed a 4-layer structural reconstruction technique at the anterior side of the shoulder, which includes capsule-labrum repair, glenoid bone grafting, and transfer of the long head of the biceps brachii (LHB). This procedure is indicated in patients who need both sling and bone fragment augmentation. The critical steps of this technique are LHB transfer and 2-layer glenoid bone grafting. We believe that this technique will enhance the field of anterior shoulder reconstruction for complicated anterior shoulder dislocation.

Shoulder stiffness is a condition of restricted glenohumeral range of motion, which can arise spontaneously or as consequence of a known cause, including surgical procedures on the shoulder. Several approaches to shoulder stiffness have been proposed and high-level evidence is available to analyze and discuss their results. The aim of this review was to summarize the current concepts on conservative and operative treatment of shoulder stiffness and discuss the results of the available studies with a high level of evidence, which should be considered to guide clinical practice. Treatment of shoulder stiffness should be tailored to the patient's clinical situation and the stage of its shoulder pathology and should aim at pain reduction, restoration of range of motion, functional regain and shortening of symptoms duration. When possible, known risk factors for primary shoulder stiffness and causes of secondary shoulder stiffness should be addressed to avoid relapse. Conservative therapy is the mainstay of treatment for shoulder stiffness and should include a multimodal and activity-oriented program. Intra-articular injection of a low dose of corticosteroid is safe and effective, provides immediate benefits, and is recommended in combination to an appropriate rehabilitation protocol. In conservative refractory cases, arthrolysis and capsular release can be performed with an arthroscopic approach.

Advances in modern arthroscopy have contributed significantly to greater flexibility and efficacy in addressing shoulder pathology. Advantages of arthroscopy include less invasive approaches, improved visualization, decreased risk of many postoperative complications, and faster recovery. As a result, arthroscopy is often preferred by both orthopaedic surgeons and patients. Common shoulder conditions that can be managed arthroscopically include rotator cuff tears, shoulder instability, and labral pathology. A thorough understanding of anatomic principles in conjunction with proper patient positioning and portal selection and placement are essential for successful arthroscopic shoulder surgery.

This article explores MR arthrography of the glenohumeral joint, including normal anatomy of the glenoid labrum, glenohumeral ligaments, and biceps labral complex. Examples of glenohumeral joint instability include the Bankart lesion, anterior labroligamentous periosteal sleeve avulsion, glenolabral articular disruption, humeral avulsion of the glenohumeral ligament, and Bennet lesion. Normal variations include the sublabral foramen, the Buford complex, and cord-like middle glenohumeral ligament. Labral tears and paralabral cysts are also discussed.

Shoulder instability is a common diagnosis that often requires surgical treatment. A detailed knowledge of the shoulder anatomy and its stabilizing structures is of utmost importance for successful treatment of shoulder instabilities. Identifying anatomic variants (e.g., sublabral hole, meniscoid labrum, cordlike middle glenohumeral ligament, and Buford complex) and distinguishing them from pathologic findings may be especially difficult, as shown by the high interobserver variability. Over the last decade, basic research and arthroscopic surgery have improved our understanding of the shoulder anatomy and pathology. In the context of shoulder instability, injuries of the glenoid (bony Bankart), injuries of the glenoid labrum superiorly (SLAP) or anteroinferiorly (e.g., Bankart, anterior labroligamentous periosteal sleeve avulsion, and Perthes), capsular lesions (humeral avulsion of the glenohumeral ligament), accompanying cartilage lesions (Hill-Sachs, glenolabral articular disruption), and rotator interval and pulley lesions, as well as signs of dynamic instability impingement (posterior-superior impingement, anterior-superior impingement) can be exactly diagnosed (magnetic resonance imaging with intra-articular gadolinium, arthroscopy) and treated (arthroscopy). Therefore the purpose of this article is to review the current literature concerning shoulder anatomy/pathology related to shoulder stability/instability to improve clinical diagnosis and surgical treatment of our patients.

Proper visualization is of paramount importance during arthroscopic rotator cuff repair. We propose a technique that significantly improves the visualization of the rotator cuff when viewing from the anterolateral or lateral portals. This "panorama" view is obtained by a release of the deep layer of the deltoid fascia, which in turn increases the space between the humerus and the deltoid muscle. This release increases the volume of the subdeltoid bursa, secondarily increasing the field of view of the subacromial space with the camera viewing from the anterolateral or lateral portals. This technical note describes a new technique useful in obtaining an excellent view of the subacromial space proving very useful in both the diagnosis and treatment of rotator cuff pathology.