Shoulder Injuries
Patient Information
The shoulder is a ball (humeral head) and socket (glenoid) joint, and the most mobile joint in the body. However, the socket (glenoid) is shallow covering less than half of the ball (humeral head) and providing little structural support. Instead, the shoulder joint is held in place by muscles and bands of connective tissue called tendons, ligaments, and labrum. Four major rotator cuff muscles (subscapularis, supraspinatus, infraspinatus and teres minor) and their tendons connect the upper arm bone (humerus) with the shoulder blade (scapula).
There are many different types of shoulder injuries and tears. Common types of acute injuries are rotator cuff tears, biceps tendon rupture, Bankart lesions, and Superior Labrum from Anterior to Posterior (SLAP) lesions. Other conditions can be more insidious in onset and not associated with an acute injury. Many of these injuries can occur from long-term overuse, such as repetitive lifting, pushing, pulling and throwing. For this reason, athletes and skilled workers are particularly prone to shoulder injuries.
Rotator Cuff Tear
The rotator cuff is made up of four different muscles and tendons. The rotator cuff is located under part of the shoulder blade and provides stability to the joint during movement. Rotator cuff injuries are fairly common. Causes of this injury may include falling, lifting and repetitive arm activities.
As patients age, the blood supply to the rotator cuff deteriorates and it becomes more sensitive to injury. Impingement on bone spurs can also create an environment for chronic pain and the development of tears.
Symptoms may include pain and tenderness in the shoulder, especially when reaching overhead, behind the back or pulling and lifting items. The patient may also experience shoulder weakness and loss of shoulder range of motion. Symptoms may show up immediately or gradually, depending on the extent of the injury.
Labral Tear
The socket of the shoulder joint is extremely shallow, and thus inherently unstable. To compensate for the shallow socket, the shoulder joint has a ring of cartilage around the socket called a labrum that forms a deeper cup for the ball portion of the humerus. This ring of cartilage increases stability of the shoulder joint, yet allows for a wide range of movements. The following describes two common labral tears.
Bankart Lesion Tear
The Bankart lesion is one of the more common causes of instability in the shoulder. It is a tear of the labrum below the middle of the glenoid socket. This type of tear can occur from stresses placed on the front of the shoulder when performing overhead activities such as throwing or serving a tennis ball. Another common way to develop a Bankart lesion is when a shoulder dislocates. As the shoulder moves out of the joint, the labrum is often torn, especially in younger patients.
Symptoms of a Bankart lesion may include a sense of instability or aching in the shoulder. You may even experience repetition of the dislocation or a catching sensation in the shoulder. Patients will often complain that they cannot trust their shoulder, fearing it may dislocate again.
SLAP Lesion Tear
SLAP is short for Superior Labrum from Anterior (front) to Posterior (back). It is a tear of the labrum above the middle of the glenoid socket. This type of labral tear is most commonly seen in overhead throwing athletes such as baseball players and tennis players. The torn labrum seen in a SLAP tear is at the top of the shoulder socket where the biceps tendon attaches to the shoulder. An injury or tear to this part of the body typically results from overuse, trauma and accidents such as falling onto an outstretched hand.
