The labrum is a layer of cartilage that is attached around the rim of the glenoid socket. It adds depth (up to 50%) to the shallow socket and serves as an attachment point for the capsule and ligaments that provide stability. At the top of the labrum is the attachment of the biceps tendon origin. The labrum, therefore, has important functions in maintaining the athletic use of the shoulder.
Labral tears are common as we get older. The primary functions of the labrum to provide stability and serve as an origin for the biceps tendon are more important for athletic endeavors such as throwing, lifting, and overhead use. Tears in older individuals are usually asymptomatic and can be managed without surgery.
Types of Labral Tears
The most common type of labral tear is the SLAP tear. SLAP stands for "superior labrum from anterior to posterior". This top portion of the labrum is where the biceps tendon originates. A forceful pull of the biceps can cause the labrum to tear or pull away from the bone. This can occur from a fall with the arm outstretched, repetitive overhead use, heavy lifting or a sudden jerk on the arm. There are multiple patterns of a SLAP tear that have been described.
The decision to surgically repair a SLAP tear should be made with caution. Many tears are degenerative (occur with normal aging) and are not the source of pain. Smaller tears may not be symptomatic. Patients who do not require heavy overhead use of the arm or do not throw with the arm can often live with a tear. Conservative treatment with rest, medications, injections and therapy may be helpful. In higher demand individuals, surgical repair is indicated. This can be performed arthroscopically. In young athletes, the labrum is reattached to the bone using suture anchors. A small plastic or absorbable screw-like device is inserted into the bone. Attached to the anchor are the sutures that are passed around the torn labrum cartilage and tied. With the labrum securely attached to the bone, it will heal in most cases. The success for repairing SLAP tears diminishes with increased age. Older patients heal better if the biceps tendon is detached from the superior labrum and reattached further down the arm. This is called a biceps tenodesis.
Anterior labral tears
Tears of the labrum in the front of the shoulder are often due to instability. If the shoulder dislocates, the humeral head is displaced over the rim of the glenoid socket. This can cause a tear of the labrum as the head translates forward. This type of tear has been called a Bankart tear. Smaller tears may heal without causing further instability. However, larger tears and younger athletic individuals have a high risk for recurrent shoulder dislocations. These tears are discussed on the shoulder instability page. .
Posterior labral tears
Tears of the labrum in the back of the shoulder (posterior) are often due to either a posterior shoulder dislocation (reverse Bankart tear) or a force on the arm pushing the shoulder backwards. Football lineman can develop posterior labral tears from blocking with the arms extended. The humeral head is pushed backward against the labrum and results in a tear. Posterior tears can also be due to arthritis. Shoulder arthritis often develops in the posterior aspect. As a result of the joint wear, the labrum can tear. These tears do not require surgical repair.
Treatment of labral tears
The treatment of labral tears has undergone significant changes since they were first recognized about 30 years ago. Initially, some surgeons felt that the labrum was not important and it was frequently excised. Arthroscopic methods to repair the labrum were invented and surgical success was soon achieved, especially in appropriately selected patients. As with any new treatment, the initial indications for repair were much greater than realistic. We now understand that many labral tears should not be repaired. Unfortunately, many surgeons are not trained on the appropriate indications for repair. A recent study demonstrated that new orthopedic surgeons had a 3 times greater incidence of performing SLAP repairs than would be indicated in the literature. Many of these were on middle age and elderly patients. There is an old adage that when you have a hammer, everything looks like a nail. It is important that an experienced shoulder surgeon does a careful history and physical exam to determine if a torn labrum should be repaired.
Key points for the treatment of labral tears
1. The labrum is an important structure for shoulder stability and the origin of the biceps tendon.
2. Symptomatic labral tears are typically seen in younger athletic individuals.
3. Tears in older individuals are usually degenerative and can be frequently be managed without surgery.
4. The arthroscopic repair of a torn labrum has become easier and therefore many repairs are being performed unnecessarily.
5. It is important to obtain a careful history and physical examination to determine if a torn labrum is the cause of the shoulder pain. The experience of a shoulder specialist, such as Dr. Payne, can help determine which tears should be repaired.
Repair of a SLAP tear
The aqua colored suture has been passed
around the torn labrum on both sides
of the biceps tendon and securely tied.
The anchor is buried in the bone of the
glenoid and not seen.