Distal biceps avulsion

 

Avulsions can be complete or partial.

Ruptures tend to occur in the dominant elbow (86%) of men (93%) in their 40s.

Risk factors

  • anabolic steroids

  • smoking has 7.5x greater risk than nonsmokers

  • hypovascularity 

  • intrinsic degeneration 

  • mechanical impingement in the space available for the biceps tendon

Pathophysiology

  • excessive eccentric tension as the arm is forced from a flexed to an extended position "flexed elbow unacceptably challenged”

  • vascular watershed

  • mechanical attrition (abrasion during pronosupination)

biceps.png
Mechanical attrition

Mechanical attrition

Vascular watershed

Vascular watershed

 

Clinical presentation

  •  A painful “pop”

  •  Weakness and pain, primarily in supination

  • Reverse Popeye sign

Imaging

  • Xray AP+L

  • MRI : Avulsion and evaluate retraction

Reverse Popeye sign

Reverse Popeye sign

MRI showing the retraction fo the avulted biceps tendon

MRI showing the retraction fo the avulted biceps tendon

Treatment

  • Supportive treatment followed by physical therapy

    • indications: older, low-demand or sedentary patients who are willing to sacrifice function

    • outcomes

      • will lose 50% sustained supination strength

      • will lose 40% supination strength

      • will lose 30% flexion strength

      • will lose 15% grip strength

  • Surgical repair of tendon to tuberosity : should be done early