A Superior Labrum Anterior to Posterior, or SLAP, tear is a specific injury affecting the ring of cartilage within the shoulder joint. This injury occurs at the top portion of the shoulder socket and is often associated with the biceps tendon attachment. While frequently seen in athletes involved in overhead sports, a SLAP tear can affect anyone following an acute injury or chronic overuse.
Anatomy of the SLAP Tear
The shoulder is a ball-and-socket joint where the head of the upper arm bone, the humerus, fits into a shallow socket on the shoulder blade, known as the glenoid. Surrounding the glenoid is the labrum, a rim of strong, fibrous cartilage that acts like a bumper to deepen the socket and improve stability. The labrum also serves as the anchor point for the long head of the biceps tendon, which extends through the shoulder joint. A SLAP tear occurs in the superior part of this labrum, extending from the front (anterior) to the back (posterior) of the biceps tendon attachment.
Damage in this area compromises the shoulder’s stability and can interfere with the function of the biceps muscle. Type II tears are the most common, involving the labrum and the biceps tendon anchor detaching from the bone. Lower-grade tears may involve only fraying of the cartilage, while higher-grade tears include a “bucket-handle” tear that extends into the biceps tendon itself. The labrum has little blood flow, which limits its ability to heal naturally.
How SLAP Tears Happen and What They Feel Like
SLAP tears can result from a sudden, traumatic event or from repetitive stress over time. Acute trauma often involves a fall onto an outstretched arm, a motor vehicle collision, or a sudden, forceful pull on the arm. These mechanisms generate a compressive force or strong traction that tears the superior labrum from the bone. Chronic tears develop through repeated overhead movements, common in sports like baseball, tennis, and volleyball, or in certain labor jobs.
Symptoms often include a deep, aching pain inside the shoulder joint. This discomfort is frequently worsened by moving the arm above the head or by throwing motions. Patients often report a mechanical sensation, such as clicking, popping, catching, or grinding when the shoulder is moved. A feeling of instability or the shoulder “locking up” may also be present, as the torn labral tissue interferes with normal joint mechanics.
Confirming the Diagnosis and Conservative Care
Diagnosing a SLAP tear begins with a physical examination, where a physician performs specific maneuvers to stress the labrum and biceps tendon. While X-rays are used to rule out fractures or other bone abnormalities, they cannot visualize the soft tissue damage of a labral tear. The most definitive non-invasive imaging test is a Magnetic Resonance Imaging (MRI) scan, often performed with a contrast dye injection, known as an MR arthrogram, to better highlight the tear.
Initial management for many SLAP tears, particularly lower-grade injuries, typically involves a conservative approach. Treatment starts with a period of rest and the use of non-steroidal anti-inflammatory drugs (NSAIDs) to manage pain and swelling. Physical therapy focuses on strengthening the muscles surrounding the shoulder, specifically the rotator cuff and periscapular muscles. The goal of this targeted strengthening is to improve the dynamic stability of the shoulder joint and compensate for the labral damage.
Surgical Intervention and Rehabilitation
Surgical intervention is reserved for patients whose symptoms fail to improve after conservative treatment, or for those with high-grade tears that compromise joint stability. The procedure is typically performed arthroscopically, using small incisions and specialized instruments to view and repair the tear. Surgeons will either debride the tear, trimming away the frayed or unstable edges of the labrum, or perform a repair by suturing the torn labrum back to the glenoid bone.
If the biceps tendon anchor is involved, the surgeon may perform a biceps tenodesis, detaching the biceps tendon from the labrum and reattaching it to a different area of the humerus. Rehabilitation begins with a period of immobilization in a sling to protect the surgical repair. Recovery is lengthy, often taking between four to six months to return to normal activities, with a full return to overhead sports sometimes requiring up to a year. Adherence to the physical therapy regimen is crucial for restoring the shoulder’s full range of motion, strength, and function.