Osteonecrosis due to drugs, unspecified ankle

This code signifies the death of bone tissue in an unspecified ankle joint, specifically caused by the use of certain medications. It indicates a condition where the blood supply to the bone is compromised due to drug-related factors, leading to bone collapse and potential joint destruction.

Apply this code when documentation clearly states osteonecrosis of the ankle is attributed to drug therapy, but the specific ankle (left or right) is not identified. Supporting documentation would include a physician's diagnosis linking the osteonecrosis to drug use, such as corticosteroids or bisphosphonates, and imaging reports confirming the condition.

• Ensure the documentation explicitly links the osteonecrosis to drug use; otherwise, consider other etiologies.
• If the specific ankle is documented (left or right), use the more specific codes M87.171 or M87.172.
• Always sequence this code after the underlying drug-induced condition, if applicable, and any associated complications.