Preoperative imaging of traumatic anterior shoulder instability: Diagnostic effectiveness of magnetic resonance arthrography and comparison with conventional magnetic resonance imaging and arthroscopy

Anterior Labrum Periosteal Sleeve Avulsion Lesions of the Shoulder: A Scoping Review

Background

Anterior labrum periosteal sleeve avulsion (ALPSA) lesion of the shoulder is defined as a labral avulsion with an intact periosteum of the glenoid neck resulting in medial malattachment of the labrum, which is both nonanatomic and nonfunctional. It is relatively rare compared with Bankart lesions, and its results are usually reported in combination with other anterior labroligamentous lesions in the literature.

Purpose

To (1) assess the size and scope of the literature on ALPSA lesions, (2) highlight the importance of this lesion, and (3) distinguish between ALPSA and Bankart lesions in diagnostic and treatment strategies.

Study Design

Scoping review; Level of evidence, 4.

Methods

The PubMed, Scopus, Embase, and Google Scholar databases were searched with the keywords "ALPSA,""anterior labrum periosteal sleeve avulsion,""anterior labral periosteal sleeve avulsion," and "anterior labroligamentous periosteal sleeve avulsion" lesion. Duplicate articles and those that did not meet the inclusion criteria were excluded, resulting in the identification of 42 relevant articles. Their references were analyzed for further data curation.

Results

This scoping review demonstrated that ALPSA lesions are difficult to clinically identify. Magnetic resonance angiography in the adduction internal rotation position is the most sensitive and specific imaging modality for identification. Optimal views are the anterosuperior portal for accurate identification and the anteroinferior portal for surgical repair during arthroscopy. Treatment begins with correctly identifying the labrum, in contradistinction to dense reactive fibrous tissue, and reattaching the labrum to the correct anatomic glenoid footprint. Chronic lesions with bone loss require either bone block or soft tissue augmentation procedures.

Conclusion

There is paucity of exclusive literature on ALPSA lesions. It is important to distinguish this lesion from the Bankart lesion as it is associated with worse outcomes. The higher failure rates of ALPSA lesion repair indicate that the current repair techniques require further refinement to improve the outcomes to the standard of Bankart lesions.

Editorial Commentary: Magnetic Resonance Arthrogram Is More Accurate and Precise Than Conventional Magnetic Resonance Imaging for Evaluating Labral Tears After First-Time Shoulder Dislocation

Recent research shows that magnetic resonance arthrogram offers better definition of certain shoulder pathology, especially labral tears, compared with magnetic resonance imaging (MRI). Conventional MRI accuracy and precision deteriorate after 2 weeks, and few health delivery environments achieve MRI within 14 days of a shoulder dislocation. Moreover, further loss of MRI accuracy is time dependent. Although magnetic resonance arthrogram should be considered a first-line imaging study when evaluating shoulder instability more than 2 weeks after the patient's injury, one must also consider clinical value and cost-effectiveness.

The glenohumeral ligaments: Superior, middle, and inferior: Anatomy, biomechanics, injury, and diagnosis

The three glenohumeral ligaments (superior, middle, and inferior) are discrete thickenings of the glenohumeral joint capsule and are critical to shoulder stability and function. Injuries to this area are a cause of significant musculoskeletal morbidity. A literature search was performed by a review of PubMed, Google Scholar, and OVID for all relevant articles published up until 2020. This study highlights the anatomy, biomechanical function, and injury patterns of the glenohumeral ligaments, which may be relevant to clinical presentation and diagnosis. A detailed understanding of the normal anatomy and biomechanics is a necessary prerequisite to understanding the injury patterns and clinical presentations of disorders involving the glenohumeral ligaments of the shoulder.