Osteonecrosis due to drugs, right toe(s)

This code signifies the death of bone tissue in the right toe(s) resulting from the adverse effects of medication. This condition, also known as avascular necrosis, occurs when the blood supply to the bone is disrupted, leading to bone collapse and potential joint destruction. The drug-induced etiology is a critical component of this diagnosis.

Apply this code when documentation explicitly states osteonecrosis of the right toe(s) and clearly links its cause to a specific drug or class of drugs. Common scenarios include patients on long-term corticosteroid therapy, bisphosphonates, or certain chemotherapy agents who develop bone pain and imaging findings consistent with avascular necrosis in the right foot digits. The medical record should specify the affected toe(s) and the causative medication.

• Ensure the documentation specifies "right toe(s)" and not a different anatomical site or laterality.
• Always sequence an external cause code (e.g., T36-T50 with a 5th or 6th character indicating adverse effect) to identify the specific drug causing the osteonecrosis.
• Differentiate from osteonecrosis due to other causes (e.g., trauma, alcoholism, idiopathic) which are classified under different M87 subcategories.