• Clinical science

Biceps tendon tear

Abstract

Biceps tendon tears 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. 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. Tears involving the long head may be managed conservatively with rest and analgesics, while biceps insertion tears require immediate surgical repair to restore functionality.

Classification

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

References:[1][2][3]

Etiology

  • Proximal biceps tear
  • Distal biceps tear
    • Primarily traumatic (mainly eccentric loading of the muscle)
    • Chronic mechanical irritation of the tendon against an irregular surface (e.g., chronic cubital bursitis)

References:[1][2][4]

Clinical features

  • Proximal biceps tear
    • Mostly painless; some tenderness may be present in the intertubercular sulcus
    • Usually, no significant loss of function
    • Distal displacement of the biceps belly upon contraction
  • Distal biceps tear
    • 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 (“Popeye sign”)
    • 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.

References:[1][2][3]

Diagnostics

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

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

References:[1][2]

Treatment

  • Proximal biceps tear
    • Mostly conservative treatment (analgesics, ice packs, rest)
    • Surgical treatment is indicated for:
      • Cosmetic improvement
      • Patients with high levels of physical activity (e.g., athletes)
      • There is chronic pain despite conservative therapy
    • Procedure: tendon repair via keyhole technique
  • Distal biceps tear
    • Rest and NSAIDs
    • Surgical refixation is necessary to regain full arm strength and function.

Surgical repair should be carried out within 2–3 weeks of injury. After this period, fibrosis leads to muscle shortening, making it impossible to approximate and attach the separated ends!
References:[1][2][3]