Osteonecrosis due to drugs, unspecified foot

This code signifies the death of bone tissue in an unspecified foot, specifically caused by the use of certain medications. This condition, also known as avascular necrosis, results from an interruption of blood supply to the bone, leading to bone collapse and potential joint destruction. The "unspecified foot" indicates that the laterality (right or left) or specific bone within the foot is not documented.

Use this code when documentation clearly states osteonecrosis of the foot and explicitly links its etiology to drug use, without specifying which foot or the exact bone affected. This diagnosis is often supported by imaging studies (e.g., MRI, X-ray) showing bone infarction and a patient history of corticosteroid use, bisphosphonates, or other implicated medications.

• Ensure the documentation explicitly states "due to drugs" as the cause of osteonecrosis. If the cause is unknown or attributed to other factors, a different subcategory of M87 would be appropriate.
• If the laterality (right or left foot) is specified in the documentation, a more specific code (M87.171, M87.172) should be used instead.
• Code any associated pain or functional limitations separately, if documented.