Idiopathic aseptic necrosis of bone, multiple sites

This code signifies the presence of bone tissue death due to impaired blood supply, occurring without an identifiable cause (idiopathic) and affecting multiple skeletal locations. It represents a non-infectious process leading to bone infarction and potential structural collapse.

Assign this code when documentation clearly indicates idiopathic avascular necrosis affecting more than one distinct bone or joint. Supporting documentation should include imaging reports (e.g., MRI, X-ray) confirming necrosis in multiple sites and physician notes ruling out secondary causes such as trauma, steroid use, or systemic diseases.

• Ensure "idiopathic" is explicitly stated or clearly implied in the documentation; otherwise, a more specific code for secondary avascular necrosis may be appropriate.
• Verify that multiple sites are affected; if only a single site is involved, use the appropriate site-specific code (e.g., M87.05- for femur).
• Do not confuse with osteomyelitis (M86.-), which is bone infection, or osteonecrosis due to specific causes (M87.1-M87.3).