Biceps tendinopathy and biceps tendon rupture

Biceps tendinopathy is a degenerative condition most commonly affecting the proximal long head of the biceps tendon near its origin from the glenoid. Early identification and effective treatment of biceps tendinopathy can prevent a proximal biceps rupture from occurring. Biceps tendon ruptures are injuries to the biceps muscle that result in the complete or partial severing of the tendon from the bone. The tendon of the long head is most commonly affected, usually as a result of trivial trauma in patients with a pre-existing, degenerative joint condition, (e.g., biceps tendinopathy). The rupture is rarely painful and usually does not cause any significant loss of function. By contrast, a tear involving the insertion of the biceps is most often the result of trauma due to overloading, is acutely painful, and entails a loss of movement in the elbow joint. Ultrasound and MRI are used to confirm the diagnosis. Tendinopathy or rupture involving the long head may be managed conservatively with rest and analgesics, while biceps insertion rupture requires immediate surgical repair to restore functionality.

• Based on location of the rupture
  • Proximal biceps tendon rupture:
    • At the origin of the long head of the biceps (95% of cases)
    • At the origin of the short head of the biceps (very rare)
  • Distal biceps tendon rupture: at the insertion of the biceps tendon (5% of cases)
• Based on extent of the rupture
  • Partial rupture
  • Complete rupture

References:^[1]

• Biceps tendinopathy ^[2]
  • Degenerative tendinosis with increasing age
  • Isolated tendonitis: due to repetitive pulling, lifting, or throwing (e.g., in rock climbers, weight lifters)
• Proximal biceps tendon rupture ^[3]
  • Commonly a result of minimal trauma; in the presence of an underlying degenerative disease of the shoulder joint (for more information, see “Pathophysiology”)
  • Predisposing conditions
    • Elderly patients
    • Pre-existing shoulder or joint conditions; (e.g., subacromial impingement, osteophytes, rheumatoid arthritis)
    • Strenuous overhead activities
    • Smoking
    • Corticosteroid medications
    • Drugs that impair tendon repair (e.g., statins)
• Distal biceps tendon rupture ^[3]
  • Primarily traumatic (mainly eccentric loading of the muscle): traumatic falls, sports injuries, manual labor (e.g., heavy lifting)
  • Chronic mechanical irritation of the tendon against an irregular surface (e.g., chronic cubital bursitis)

As mentioned in etiology, distal biceps tears are primarily traumatic whereas underlying degenerative disease (e.g., biceps tendinopathy) can lead to proximal tears.

• Biceps tendinopathy ^[2]
  • Tendonitis; (inflammation) or tendinosis; (degeneration) of the proximal long head of the biceps tendon at its origin from the glenoid
  • Tendonitis → chronic tenosynovitis → degenerative tendinosis → biceps tendon rupture
  • Chronic microtrauma increases with age → ↑ insidious inflammation → fraying of the tendon

Biceps tendinopathy

• Gradual onset of anterior shoulder pain that worsens with lifting or overhead reaching

• Point tenderness at the bicipital groove when the arm is 10° internally rotated
• Clinical tests: Yergason test and Speed test (See “Examination of the long head of the biceps tendon”)

Proximal biceps tendon rupture ^[1]

• Mostly painless; some tenderness may be present in the intertubercular sulcus

• Usually, no significant loss of function
• Popeye sign: Distal displacement of the biceps belly upon contraction

Distal biceps tendon rupture

• Acute, stabbing pain
• Hematoma in the medial region of the cubital fossa
• Limitation of flexion and partial or complete limitation of supination at the elbow joint
• Swelling in the upper arm region created by the recoiled, shortened biceps muscle
• Proximal displacement of the biceps belly upon contraction

Hook test

• Procedure: The patient is asked to actively flex the elbow at 90° and fully supinate the forearm → the index finger is then placed under the lateral edge of the biceps tendon in the cubital fossa → an attempt is then made to “hook” the tendon (pull it upwards) with the index finger
• Interpretation: With an intact or partially intact biceps tendon, the finger can be inserted 1 cm beneath the tendon, and the subsequent upward movement will be hindered by resistance from the tendon; loss of continuity of the tendon would allow the hooked finger to slip upwards without resistance, and thus suggest a complete tear.

Biceps squeeze test

• Procedure: The clinician squeezes the belly of the biceps with the patient's elbow between 60 and 80° of flexion and the forearm in pronation
• Interpretation: no resulting supination of the patient's forearm or wrist indicates a distal biceps tendon rupture

Diagnosis is primarily clinical. Imaging modalities are used to confirm the diagnosis and determine the extent and location of the rupture.

• Ultrasound: shows atypical displacement of the biceps belly
• X-ray: to exclude fractures
• MRI: helps distinguish between complete and partial rupture

• General
  • Conservative management (e.g., analgesics, ice packs, avoidance of overhead arm movements)
  • NSAIDS
• Biceps tendinopathy ^[2]
  • Physical therapy
  • Consider subacromial glucocorticoid injections or surgical management if no improvement after 3 months
• Proximal biceps tendon rupture
  • Surgical treatment is indicated for:
    • Cosmetic improvement
    • Patients with high levels of physical activity (e.g., athletes)
    • Chronic pain despite conservative therapy
  • Procedure: biceps tenodesis (tendon repair via keyhole technique)
• Distal biceps tendon rupture: Surgical repair is necessary to regain full arm strength and function.

Surgical repair should be carried out within 2–3 weeks of rupture. After this period, fibrosis leads to muscle shortening, making it impossible to approximate and attach the separated ends.

References:^[1]