Idiopathic aseptic necrosis of right fibula

This code signifies avascular necrosis (AVN) of the right fibula where the underlying cause is unknown (idiopathic) and not due to infection (aseptic). It involves the death of bone tissue due to a lack of blood supply, leading to bone collapse and potential joint destruction.

Apply this code for patients diagnosed with idiopathic avascular necrosis specifically affecting the right fibula. Documentation should clearly state "idiopathic," "aseptic," and specify the "right fibula" as the affected site. This code is appropriate when no other identifiable cause for the AVN (e.g., trauma, corticosteroid use, sickle cell disease) has been determined.

• Ensure documentation explicitly states "idiopathic" and "aseptic" to differentiate from other forms of osteonecrosis.
• Verify laterality; this code is specific to the right fibula. Use M87.065 for the left fibula or M87.069 for unspecified fibula.
• Do not confuse with osteomyelitis (infection of the bone) or traumatic necrosis, which have different code assignments.