Labral Tear of the Shoulder

The glenoid labrum is a fibrocartilage rim that deepens the socket by about 50% and anchors the capsule, ligaments and the long head of the biceps. Tears are classified by site.

Superior labrum anterior to posterior (SLAP) types:

• I: fraying with a stable attachment
• II: detachment of the labrum and biceps anchor (the commonest)
• III: bucket handle tear with an intact anchor
• IV: extension into the biceps tendon
• Further types extend into anterior, posterior or capsular structures

Other patterns include posterior tears from posterior instability and degenerative fraying. Mechanisms are a fall on the outstretched arm, traction, a direct blow, and the peel back force of overhead throwing. Degenerative labral changes appear on MRI in most people over 40 and are often painless, so imaging must be interpreted with the examination.

Complications are mechanical symptoms, instability, cartilage damage and paralabral cysts that compress the suprascapular nerve at the spinoglenoid notch (infraspinatus weakness and wasting).

• Deep, poorly localised shoulder pain with overhead use, throwing and lifting
• Catching, clicking, a dead arm sensation, reduced throwing velocity and night pain
• Positive O'Brien active compression test (pain with the thumb down that eases with palm up), biceps load II test, crank test, and pain on resisted biceps with the arm abducted
• Posterior pain with a posterior load test in posterior tears
• Infraspinatus wasting and weakness with a paralabral cyst
• Red flags: recurrent instability, locked shoulder, muscle wasting, fever and unrelenting night pain

• Clinical assessment with a combination of provocative tests.
• Radiographs (anteroposterior, scapular Y, axillary) to exclude fracture, bony defects and arthritis.
• MR arthrography (dilute gadolinium injected into the joint, with abduction external rotation views): sensitivity about 90%. Conventional MRI is less sensitive.
• CT arthrography when MRI is contraindicated.
• Electromyography if a nerve injury is suspected.
• Arthroscopy as the definitive test when symptoms persist.

Differentials: biceps tendinopathy, rotator cuff tear, internal impingement, glenohumeral instability, acromioclavicular arthritis, cervical radiculopathy.

Non-operative (type I, degenerative lesions, low demand):

• Rest from provocative activity, paracetamol 1 g orally every 6 hours, and ibuprofen 400 mg orally every 8 hours with food for up to 7 days.
• Physiotherapy for 3 to 6 months: scapular stabilisation, cuff strengthening and posterior capsule stretching.
• Intra articular triamcinolone acetonide 40 mg with lidocaine 1% 5 mL for flares.

Surgery after failed rehabilitation or for mechanical symptoms:

• Type I: debridement.
• Type II under 35 to 40 years: arthroscopic repair with 1 to 3 suture anchors.
• Type II over 40 years: biceps tenodesis (interference screw 8 mm or suture anchor) or tenotomy preferred, since repair carries more stiffness and failure.
• Type III: excision of the bucket handle fragment.
• Type IV: debridement of the biceps if under 50% involved, tenodesis if more.
• Paralabral cyst: repair the labrum and decompress the cyst. The nerve usually recovers.
• Cefazolin 2 g IV before incision (3 g if over 120 kg).
• Postoperative: sling for 4 weeks, no resisted biceps for 6 to 8 weeks, throwing at 4 to 6 months, and return to full overhead sport at 9 to 12 months.

Outcomes: good results in 70 to 90%. About 60 to 70% of overhead athletes return to their previous level.

Complications: stiffness (5 to 10%), failure of repair, nerve injury and infection.

Follow up at 2 weeks, 6 weeks, 3 and 6 months. Counsel on a structured throwing program.