Introduction

Since orthopaedic surgeons began using the arthroscope to diagnose and treat shoulder problems, several new conditions have recently been discovered. One of these is an injury to a small structure in the shoulder called the labrum. A labral tear can be very difficult to diagnose, but typically it involves pain, unusual movement and the sensation of instability in the shoulder.

Torn Labrum

Anatomy

The shoulder is made up of three bones: the scapula (shoulder blade), the humerus (upper arm bone) and the clavicle (collarbone). A part of the scapula, called the glenoid, makes up the socket of the shoulder. Because this socket is very shallow and flat, a rim of soft tissue, called the labrum, acts like a gasket and turns the flat glenoid surface into a deeper socket that molds to the head of the humerus for a better fit. Several shoulder tendons and ligaments attach to the labrum to help maintain shoulder stability.

End View of Scapula

The labrum can become caught between the socket and the humerus and tear. This flap of tissue can move in and out of the joint and become caught between the humeral head and glenoid socket, causing pain, catching, and shoulder instability.

labral tear of scapula

Causes

The labrum can become caught between the socket and the humerus and tear. This flap of tissue can move in and out of the joint and become caught between the humeral head and glenoid socket, causing pain, catching, and shoulder instability.

Symptoms

The main symptom of a labral tear is usually a sharp, catching type sensation in the shoulder with movement. A vague aching for several hours may follow this. This catching feeling may occur only with certain movements of the shoulder, while otherwise the shoulder may feel normal and pain-free.

Diagnosis

The diagnosis of a labral tear may be suggested by the history of the condition and a physical examination. Several specific movements may cause the symptoms. With the arm raised overhead, there may be pain, and the catching sensation may be felt as the arm is raised. If the arm is raised in front of the body, with the palm of the hand facing upward, pain may be felt when downward pressure is applied.

Labral tears are sometimes visible on a magnetic resonance imaging (MRI) scan or in a computerized axial tomography (CAT) scan when a special dye has been injected into the shoulder. An MRI scan is a special radiological test where magnetic waves are used to create pictures that look like slices of the shoulder. The MRI scan shows the bones, tendons and ligaments of the shoulder.

A CAT scan is an older test that uses computer enhanced X-rays to show slices of the shoulder. Because the CAT scan uses X-rays, the soft tissues do not show up. The special dye is necessary to show the outline of the labrum. If there is a tear, the dye may leak into the tear and show up on the CAT scan. These two tests are not very accurate in detecting this problem.

Diagnosing a labral tear can be extremely difficult, and the diagnosis may rely on looking into the shoulder with the arthroscope, which is a small TV camera that can be inserted into the shoulder joint. The shoulder joint is viewed on a TV monitor. This allows the surgeon to look directly at the labrum and see if it is torn.

Shoulder Arthroscopy

Treatment

Since the symptoms of a labral tear may be made worse by instability, a rehabilitation program to strengthen the rotator cuff muscles may be started by a physical therapist. Anti-inflammatory medications, such as aspirin or ibuprofen, may help the pain. If the problem persists, surgery may be required to confirm the diagnosis and attempt to treat the problem.

Surgical treatment for this condition is still evolving, since the problem has not been recognized for long enough to adequately evaluate the results of different treatments through surgery. The arthroscope can be used to treat the torn labrum in many cases. If the tear is small and is primarily getting caught as the shoulder moves, simply removing the loose part of the labrum may help the symptoms.

Surgical Repair

If the tear is larger, the shoulder may also be unstable, meaning that it is too loose. If this is the case, the labral tear may need to be repaired instead of removed. Several new techniques allow the surgeon to place small staples into the labrum through the arthroscope and attach the labrum to the bone of the shoulder socket (glenoid). If the tear is too large to repair through the arthroscope, an incision may have to be made in the front of the shoulder to repair the torn labrum

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