The shoulder is a ball and socket joint. The socket of the shoulder is surrounded by a ring of soft tissue, called the labrum.
The socket, or glenoid, is fairly shallow, and the labrum serves to deepen the cavity of the glenoid.
This is important because the labrum helps to keep the “ball” – the head of the arm bone (the humerus) – in place. The labrum can tear as a result of trauma or with wear and tear.
The normal labrum is a smooth ring of tissue that surrounds the socket of the shoulder. Labral tears are often caused by a direct injury to the shoulder, such as falling on an outstretched hand.
The biceps tendon attaches to the top part of the labrum. The biceps is the large muscle on the front of your upper arm. Sports can cause injuries to the labrum when the biceps tendon pulls sharply against the front of the labrum. Baseball pitchers are prone to labral tears because the action of throwing causes the biceps tendon to pull strongly against the top part of the labrum. Weightlifters can have similar problems when pressing weights overhead. Golfers may tear their labrum if their club strikes the ground during the golf swing. Labral tears can also develop over time from day to day use as degenerative tears related to aging.
Symptoms of a Labral Tear:
The main symptom caused by a labral tear is a sharp pop or catching sensation in the shoulder during certain shoulder movements. This may be followed by a vague aching for several hours. At other times, the tear may not cause any pain. Shoulder instability can result from a damaged labrum, and may cause the shoulder to feel loose, as though it slips with certain movements.
Labral tears can usually be diagnosed with a history and physical examination. MRI (magnetic resonance imaging) scans are very good at showing the extent and severity of a rotator cuff tear. An MRI uses magnetic waves to create a series of pictures in slices to show the bones, tendons, muscles and cartilage in the shoulder. A closed MRI is usually preferred over an open MRI, as a closed MRI is much more accurate at showing details in the shoulder anatomy.
Type I Labral Tears
When the tissue of the top part of the labrum tears, it can occur as fraying of the tissue. This is called a Type I labral tear (as opposed to a Type II labral tear as described below). For most patients, Type I labral tears are best treated with physical therapy. Physical therapy will help regain any lost motion, and it will condition the other muscles of the shoulder – allowing more efficient use of the arm, giving a chance for the symptoms of the labral tear to resolve. Icing the shoulder twenty minutes twice daily will also help reduce inflammation and relieve pain – it is especially helpful to ice the shoulder before bed if sleeping is difficult. A corticosteroid injection into the shoulder may be helpful in further reducing pain and inflammation. An arthroscopy of the shoulder (see below) may be a treatment option if pain continues despite physical therapy and a corticosteroid injection. During arthroscopy, the torn portion of the labrum is removed, leaving the healthy, intact fibers of the labrum.
Type II Labral Tears:
A type II labral tear is when the labrum actually detaches from the bone. In this case, an arthroscopy is usually recommended to repair the labrum. During arthroscopy, anchors are placed into the bone, and stitches attached to the anchors are passed through the labrum. When these stitches are tied, the labrum is pulled back down against the bone so it can heal in the proper location.
After a labral repair, the labrum must be able to heal in place. While it is important to move the shoulder to prevent scar tissue, or a frozen shoulder, from developing, there should only be passive motion of the shoulder. Passive motion is when a physical therapist moves the shoulder for the patient – the patient should not make any active effort to move the shoulder by himself. Usually, these passive motion only restrictions apply for four weeks.
Shoulder arthroscopy is generally an outpatient procedure in which the patient goes home the day of surgery. Small incisions (approximately 1cm in length) are made in the shoulder, through which a fiber optic camera and other instruments are inserted to perform the surgery. The shoulder is visually examined, including the cartilage, tendons and bursa of the shoulder. Any necessary procedures, such as a labral repair, are then performed as described above.