Anatomy of the Shoulder Joint:
The shoulder joint consists of the upper arm bone (humerus), the shoulder blade (scapula), and the collarbone (clavicle). The head of the humerus fits into a rounded socket in the scapula called the glenoid. Cartilage surrounds the edges of the glenoid and is called the labrum. This cartilage is tough and fibrous and helps stabilize the shoulder joint. Moreover, it is connected to ligaments and muscles of the shoulder, including the biceps muscle.
What is a SLAP Tear?
SLAP tears, or Superior Labrum Anterior and Posterior tears, are tears of the upper labrum. These tears occur in front of and behind the connection point of the biceps muscle.
What causes SLAP Tears?
SLAP tears may occur over time from repeated use of overhead motions, such as throwing or lifting weights. Common sports associated with SLAP tears are baseball, swimming, or weight-lifting. SLAP tears may also occur with sudden, jerky movements such as lifting heavy objects, or from falling on an outstretched hand. Lastly, the labrum may wear out with age, leading to tears.
Symptoms of SLAP tears:
Symptoms of a SLAP tear include pain associated with overhead motions, clicking and popping with movement of shoulder, loss of shoulder muscle strength and endurance, limited ability to rotate the arm inwards and to lie on the shoulder. SLAP tears are often seen with other injuries, such as injuries to the biceps muscle and the rotator cuff, a group of muscles that keep the humerus in the glenoid.
Diagnosis of SLAP tears:
SLAP tears may be diagnosed using a series of tests:
Tenderness at the rotator interval: the examiner palpates the rotator interval, an area located in front of and above the glenohumeral joint capsule, a supportive structure made up of ligaments or fibrous tissue that connects bones together, that covers part of the humerus and the rim of the glenoid. The rotator interval is a triangular area that forms a unique gap in front of the rotator cuff, and tenderness at this area may be indicative of a SLAP tear.
Biceps load test II: the patient lays on their back and the shoulder is brought 120° away from the torso and rotated outward. The below is bent at 90° with the inner side of the forearm facing upwards. The examiner then provides resistance while that patient is instructed to bend the elbow towards the body. The test is positive if there is an increase in symptoms during movement.
O’brien test: The patient is sitting or standing with their arm held in front of their body at a 90° from the torso. The arm is then brought towards the midline, horizontally, by 10-15°. The arm is rotated inwards with the palm held facing down. The examiner presses downwards while the patient is required to apply an upwards force. Pain or clicking at the shoulder is indicative of a positive test. Then, the patient holds the arm in front of themself with the palm facing upwards and externally rotates the arm. The examiner pushes downwards while the patient resists the downwards force. If the pain and clicking produced by the first test is relieved, the O'brien's test is considered positive.
Anterior apprehension test: The patient lays on their back while the examiner holds the elbow at a 90° angle and arm held at a 90° angle away from the torso. The examiner will then externally rotate the shoulder, and the test is considered positive when the patient resists rotation or is apprehensive.
Speeds Test: The examiner places the patient's arm in front of the patient, with the arm held 90° from the torso. The underside of the arm and palm is facing upwards while the examiner presses downwards. Pain in the biceps tendon is indicative of a positive test.
Yergason’s test: The patient is seated or standing with the upper arm held at the patient’s side and the elbow bent at a 90°. The underside of the arm and palm are facing downwards. The patient then rotates their arm outwards and tries to bring the underside of their arm to face upwards while the examiner resists the motion by holding the patient’s forearm just below the wrist. The test is considered positive if pain is reproduced.
Compression test: Also known as the Crank Test, the patient sits upright or lays on their back with the arm held to their side, 90° away from the torso. The elbow is bent at 90°, and the examiner presses into the humerus at the elbow joint with one hand while they rotate the arm with the other hand. The test is considered positive if pain is reproduced with or without clicking.
Dynamic labral shear test: the patient stands up while the examiner stands behind the patient. The examiner holds the wrist of the arm of the affected shoulder with one hand. The arm is held in front of the patient 90° from the torso, and the elbow is also bent at a 90°.The examiner then applies pressure at the head of the humerus from behind the shoulder with their other arm. The arm is raised upwards from 90° to 150°, and the test is considered positive if the examiner feels a click or if pain is reproduced as the arm is raised from 90° to 150°.
Diagnostic Imaging: MRIs and CT scans are also used to diagnose SLAP lesions. MR arthrograms, which involve the injection of contrast material into the shoulder, are better able to detect SLAP lesions than MRIs.
Types of SLAP lesions:
Type I: degeneration of the labrum with no damage to the bicpes tendon, tissue that connects muscle to bone. These are found in patients who are middle-aged and older.
Type II: detachment of the upper part of the labrum and biceps tendon.
Type III: the biceps tendon remains attached to the bone while the labrum is caught in the shoulder joint.
Type IV: involves tears of the upper labrum that extend into the biceps tendon.
Treatment:
Most patients with SLAP lesions are treated surgically. Conservative treatment, such as abstaining from activities, use of NSAIDs, and steroid injections may help alleviate symptoms. Physical therapy focusing on strength, stability, and motion may then be used.
Type I: debridement of the labral lesion using an arthroscope, a small camera inserted into the shoulder that displays images onto a monitor.
Type II: arthroscopic fixation, or reattachment of the upper labrum and biceps tendon with the aid of an arthroscope. Elite throwing athletes may be treated with an absorbable tack. For patients older than 36, a surgical procedure called biceps tenodesis is a more effective treatment. During biceps tenodesis, the biceps tendon is detached from the labrum and reattached to the humerus.
Type III: arthroscopic debridement of the labral lesion.
Type IV: repaired with sutures.
Post-operative recovery:
Patients use a sling for their shoulder 3 to 4 weeks postoperatively, followed by rehabilitation. During the 3 to 4 weeks of immobilization, patients are allowed to utilize elbow ranges of motion. Between 4 and 8 weeks, patients work on shoulder range of motion. At 8 weeks, patients begin resistance exercises and increasing shoulder strength. Patients may begin to gradually return to activity at 4 to 6 months.
