ALPSA lesion

ALPSA Lesion

An ALPSA lesion (Anterior Labroligamentous Periosteal Sleeve Avulsion) is a specific type of shoulder injury that involves the detachment of the anterior labrum from the glenoid rim, with the periosteum remaining intact. This condition is often associated with shoulder dislocation and can lead to shoulder instability.

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MRI image showing an ALPSA lesion.

Anatomy and Pathophysiology

The shoulder joint is a complex structure that allows for a wide range of motion. It is stabilized by the glenoid labrum, a fibrocartilaginous rim attached to the margin of the glenoid cavity. In an ALPSA lesion, the anterior labrum is avulsed from the glenoid, but the periosteum remains attached, allowing the labrum to displace medially and inferiorly. This displacement can compromise the stability of the shoulder joint, leading to recurrent dislocations.

Clinical Presentation

Patients with an ALPSA lesion typically present with symptoms of shoulder instability, such as a feeling of the shoulder "slipping" or "giving way," especially during activities that involve overhead motion. There may also be pain, particularly with movements that stress the anterior shoulder structures.

Diagnosis

Diagnosis of an ALPSA lesion is primarily made through imaging studies. Magnetic Resonance Imaging (MRI) is the preferred modality as it provides detailed images of the soft tissues, including the labrum and periosteum. The MRI image of an ALPSA lesion shows the characteristic medial and inferior displacement of the labrum.

Treatment

The treatment of an ALPSA lesion depends on the severity of the instability and the patient's activity level. Conservative management may include physical therapy to strengthen the rotator cuff muscles and improve shoulder stability. However, surgical intervention is often required to reattach the labrum to the glenoid and restore normal anatomy. Arthroscopic surgery is commonly performed, where anchors and sutures are used to secure the labrum back to the bone.

Prognosis

With appropriate treatment, the prognosis for patients with an ALPSA lesion is generally good. Surgical repair typically results in a stable shoulder with a low risk of recurrent dislocation. Rehabilitation plays a crucial role in recovery, focusing on restoring range of motion and strengthening the shoulder muscles.

Related Pages

• Shoulder dislocation
• Glenoid labrum
• Rotator cuff
• Shoulder joint