SLAP Lesion

Anatomy of the Shoulder Joint

The shoulder joint is the largest joint in the upper limb, connecting it to the shoulder girdle. It is a ball-and-socket joint characterized by a wide range of motion in various directions: flexion and extension, abduction and adduction, external and internal rotation. Due to its high mobility and complex anatomical structure, it is prone to various injuries and traumas. The humeral head is significantly larger than the glenoid cavity, whose depth is increased by the labrum. The upper part of the labrum is directly connected to the tendon of the long head of the biceps muscle. Some fibers of this tendon attachment extend into the labrum area, which is why injuries often involve simultaneous damage to the tendon and part of the labrum.

Classification of SLAP Lesions:

• Type I: Degeneration or fraying of the labrum without instability.
• Type II: The most common type (50% of cases), involving detachment of the superior labrum from the glenoid.
• Type III: A "bucket-handle" tear, with part of the tendon and labrum still attached to the glenoid.
• Type IV: A "bucket-handle" tear extending into the biceps tendon.

Causes of SLAP Lesions

SLAP lesions most frequently occur in athletes participating in throwing sports, particularly throwers performing overhead throwing motions (e.g., javelin, discus, shot put, as well as basketball, volleyball, tennis, or baseball). The etiology is not entirely clear, with several potential mechanisms proposed. Most cases result from microtrauma that accumulates and leads to a SLAP lesion. A significant number of patients report direct external force to the shoulder, such as an impact during a fall. Another common mechanism is a strong pull on the arm, such as when falling and suddenly grabbing a bar. These injuries can also occur in individuals improperly lifting heavy weights in the gym. For throwers, labral tears or muscle injuries typically occur during the throwing phase when the biceps muscle decelerates elbow extension.

Symptoms of SLAP Lesions

• A sensation of clicking, locking, or grinding.
• Reduced range of motion.
• Pain during shoulder movements or when maintaining certain shoulder positions.
• Pain when lifting objects, especially overhead.
• Pain when lying on the affected shoulder.
• Sharp pain combined with loss of control over the limb during maximum external rotation coupled with abduction.
• Reduced shoulder strength.

Most SLAP lesions are accompanied by other shoulder pathologies, such as rotator cuff tears or joint instability.

Diagnosis of SLAP Lesions

The cornerstone of diagnosis is the medical history. The orthopedic surgeon will inquire whether the patient remembers a specific injury or activities that cause shoulder pain, as well as the most common symptoms and the circumstances under which they occur. A physical examination follows, assessing range of motion, strength, and shoulder stability. The physician may perform specific tests by positioning the arm in various positions to elicit pain symptoms. Imaging diagnostics include X-rays to rule out other shoulder issues, such as fractures. Magnetic resonance imaging (MRI), often with contrast, is the next step to visualize soft tissues like the labrum. Diagnosing SLAP lesions can sometimes be challenging, as symptoms often mimic other shoulder pathologies.

Treatment of SLAP Lesions

In most cases, initial treatment for SLAP injuries is non-surgical. Physicians may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and swelling. Physical therapy follows, with a tailored exercise program developed by a qualified physical therapist to strengthen the shoulder and restore joint mobility. Unfortunately, conservative treatment often fails to yield satisfactory results. Surgical treatment depends on whether there is detachment of the biceps tendon or the anterosuperior part of the labrum.

For Type I and III injuries, frayed labrum tissue is debrided without the need for stitching.
Type II injuries require arthroscopic repair and fixation of the detached fragment using special implants.
In Type IV SLAP lesions involving more extensive damage, both tendon and labrum are sutured.

Postoperative Rehabilitation

The initial postoperative period focuses on healing and protecting the shoulder. The operated arm should remain immobilized in a shoulder brace for 2 to 6 weeks post-surgery, depending on the severity of the injury and the complexity of the procedure. Once pain and swelling subside, a physical therapy program begins, tailored to the specific injury. The main focus is on restoring flexibility to prevent shoulder stiffness. Full passive range of motion is typically achieved within 10-14 days post-surgery. Active movements are allowed only after the 8th day. Gradually, strengthening exercises for the shoulder girdle are added to rehabilitation. If recovery proceeds as planned, the patient may return to sports activities between the 7th and 10th week post-surgery. For throwers, return to throwing practice may take 3 to 4 months after surgery.

Prognosis

The rehabilitation program after surgery largely depends on the extent of surgical intervention required to repair the biceps tendon attachment.

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References:

• "Biomechanical analysis of isolated type II SLAP lesions and repair" - Vahé R., Panossian MD, Teruhisa, Mihata MD, James E.Tibone MD, Michael J., Fitzpatrick MD, Michelle H., McGarry MS, Thay Q., Lee PhD - Journal of Shoulder and Elbow Surgery - Volume 14, Issue 5, September–October 2005, Pages 529-534
• Sports-Health - "SLAP Tear Shoulder Injury and Treatment" - Terry Gemas, MD - 2016
• Ortho Bullets - "SLAP Lesion" - Matthew J., Steffes MD, Patrick C., McCulloch MD, Orthobullets Team - 2021