Idiopathic aseptic necrosis of unspecified finger(s)

This code signifies the spontaneous death of bone tissue in an unspecified finger due to a lack of blood supply, without an identifiable cause such as trauma or infection. This condition, also known as avascular necrosis or osteonecrosis, leads to bone collapse and subsequent joint destruction.

Use this code when documentation clearly indicates idiopathic avascular necrosis affecting any finger, and the specific finger (e.g., thumb, index) is not specified. This diagnosis is typically made based on imaging studies (X-ray, MRI) showing characteristic bone changes and exclusion of other etiologies.

• Ensure the documentation explicitly states "idiopathic" or "aseptic" and that no specific finger is identified.
• If a specific finger is documented (e.g., index finger), use the more precise anatomical code (e.g., M87.041 for thumb, M87.042 for index finger).
• Do not use this code if the avascular necrosis is secondary to trauma, steroid use, or other known causes; instead, select a code from category M87.1-M87.3.