Osteonecrosis due to drugs, left ankle

This code indicates the death of bone tissue in the left ankle joint 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 joint destruction.

Apply this code when documentation clearly states osteonecrosis of the left ankle and explicitly links its etiology to drug use. This typically occurs in patients with a history of corticosteroid therapy, bisphosphonate use, or other medications known to cause avascular necrosis.

• Ensure the documentation specifies "left ankle" and explicitly attributes the osteonecrosis to drug use.
• Do not use this code for osteonecrosis due to other causes (e.g., trauma, alcoholism, idiopathic).
• Code any associated pathological fractures or complications separately.