A SLAP tear is an injury to the labrum of the shoulder, which is the ring of cartilage that surrounds the socket of the shoulder joint.
Your shoulder is a ball-and-socket joint made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle).
The head of your upper arm bone fits into a rounded socket in your shoulder blade. This socket is called the glenoid. Surrounding the outside edge of the glenoid is a rim of strong, fibrous tissue called the labrum. The labrum helps to deepen the socket and stabilize the shoulder joint. It also serves as an attachment point for many of the ligaments of the shoulder, as well as one of the tendons from the biceps muscle in the arm.
The labrum deepens the socket of the shoulder joint, making it a stronger fit for the head of the humerus.
The term SLAP stands for Superior Labrum Anterior and Posterior. In a SLAP injury, the top (superior) part of the labrum is injured. This top area is also where the biceps tendon attaches to the labrum. A SLAP tear occurs both in front (anterior) and back (posterior) of this attachment point. The biceps tendon can be involved in the injury, as well.
Injuries to the superior labrum can be caused by acute trauma or by repetitive shoulder motion. An acute SLAP injury may result from:
▪ A motor vehicle accident
▪ A fall onto an outstretched arm
▪ Forceful pulling on the arm, such as when trying to catch a heavy object
▪ Rapid or forceful movement of the arm when it is above the level of the shoulder
▪ Shoulder dislocation
People who participate in repetitive overhead sports, such as throwing athletes or weightlifters, can experience labrum tears as a result of repeated shoulder motion.
Many SLAP tears, however, are the result of a wearing down of the labrum that occurs slowly over time. In patients over 40 years of age, tearing or fraying of the superior labrum can be seen as a normal process of aging. This differs from an acute injury in a person under the age of 40.
The common symptoms of a SLAP tear are similar to many other shoulder problems. They include:
• A sensation of locking, popping, catching, or grinding
• Pain with movement of the shoulder or when holding the shoulder in specific positions
• Pain with lifting objects, especially overhead
• A decrease in shoulder strength
• A feeling that the shoulder is going to “pop out of joint”
• Decreased range of motion