The shoulder joint is the body’s most flexible, allowing for an impressive range of motion, but this flexibility also makes it susceptible to injury. A key component of its stability and function is the labrum, a specialized rim of cartilage.
Understanding the Labrum and Tears
The shoulder joint resembles a ball and socket, where the head of the upper arm bone (humerus) fits into a shallow socket on the shoulder blade (glenoid). The labrum is a ring of fibrous cartilage that surrounds the glenoid rim, deepening it by up to 50% and enhancing the humeral head’s fit. This rim also serves as an attachment point for ligaments and tendons, including the biceps tendon, contributing to shoulder stability.
A labrum tear occurs when this cartilaginous rim is damaged. Common types of labral tears include SLAP (Superior Labrum Anterior to Posterior) tears, which occur at the top of the labrum where the biceps tendon attaches, extending from front to back. Bankart tears are typically found at the front and lower part of the glenoid, often associated with shoulder dislocations. Tears can also happen at the back of the shoulder, known as posterior labral tears.
Identifying Causes and Symptoms
Shoulder labrum tears can result from acute traumatic incidents or repetitive stress. Falling onto an outstretched arm, a direct blow to the shoulder, or a sudden, forceful pull on the arm are common causes of acute tears. Dislocated shoulders, particularly anterior dislocations, frequently lead to Bankart tears.
Repetitive overhead motions, often seen in athletes participating in sports like baseball, tennis, or weightlifting, can also cause labrum tears due to chronic overuse. Degenerative changes from aging can weaken the labrum, making it more prone to tearing, especially in individuals over 40. Structural abnormalities in the joint or certain connective tissue disorders may also increase susceptibility.
Symptoms often include persistent shoulder pain, which can feel deep within the joint and worsen with specific movements like reaching overhead or across the body. Patients might experience a clicking, popping, grinding, or catching sensation in the shoulder during movement. A feeling of instability, or the sensation that the shoulder is slipping out of place, is also a common symptom, particularly with Bankart lesions. Decreased range of motion and reduced shoulder strength can limit daily activities and athletic performance.
Diagnosing a Labrum Tear
Diagnosing a shoulder labrum tear typically involves a medical history, physical examination, and imaging tests. During the physical examination, a doctor will assess the shoulder’s range of motion, pain levels, and tenderness. Specific physical tests, such as the O’Brien test or active compression test, may be performed to indicate a labral injury, though these tests alone are not always definitive.
Imaging techniques are crucial for confirming a diagnosis and assessing the tear’s severity and location. Magnetic Resonance Imaging (MRI) is commonly used, frequently with a contrast dye injection (MRI arthrogram) to highlight the labrum and any tears more clearly. X-rays may also be taken to rule out other issues, such as fractures or arthritis. In some cases, a CT scan or musculoskeletal ultrasound might be utilized for additional information.
Treatment and Rehabilitation
Treatment for a shoulder labrum tear varies depending on its type, size, location, and the patient’s activity level and symptoms. For milder tears, non-surgical approaches are often the initial recommendation. These conservative treatments typically involve rest, activity modification to avoid aggravating movements, pain management through anti-inflammatory medications, and applying ice to reduce swelling and discomfort. Corticosteroid injections into the shoulder joint may also reduce inflammation and pain in some cases.
Physical therapy plays a central role in both non-surgical and post-surgical rehabilitation. A physical therapist designs a program to strengthen the muscles surrounding the shoulder, including the rotator cuff and scapular muscles, which helps to stabilize the joint and reduce stress on the labrum. Exercises focus on improving range of motion, flexibility, and overall shoulder function, with movements tailored to individual needs and to prevent re-injury.
If conservative treatments do not alleviate symptoms or for more severe tears, surgical intervention may be necessary. Arthroscopic repair is a minimally invasive procedure where a surgeon makes small incisions to insert an arthroscope and specialized instruments into the shoulder joint. During this procedure, the torn labrum is either reattached to the bone using sutures and anchors or, less commonly, the damaged portion is smoothed or removed. This aims to restore stability and function to the shoulder.
Following surgery, rehabilitation is a phased process for recovery. The arm is typically immobilized in a sling for four to six weeks to protect the healing tissue. Initial rehabilitation focuses on pain control and gentle passive range of motion exercises, where the arm is moved passively. As healing progresses, active-assisted range of motion exercises begin, followed by strengthening exercises for the rotator cuff and scapular muscles. Full recovery can take several months, with a gradual return to daily activities and sports-specific training, typically ranging from three to nine months depending on the tear and individual progress.