Osteonecrosis due to drugs, left foot

This code signifies the death of bone tissue in the left foot resulting from the use of certain medications. 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.

Apply this code when documentation explicitly states osteonecrosis of the left foot and attributes its etiology to drug therapy. Common drug classes implicated include corticosteroids and bisphosphonates. Supporting documentation should include imaging reports (e.g., MRI, X-ray) confirming osteonecrosis and a clear link to drug use.

• Always code the specific drug causing the osteonecrosis as an adverse effect (T36-T50 with 5th or 6th character 5) as an additional diagnosis.
• Ensure the laterality (left foot) is clearly documented; do not use unspecified codes if laterality is known.
• Distinguish from osteonecrosis due to other causes, such as trauma or sickle cell disease, which have different ICD-10-CM codes.