Osteonecrosis in diseases classified elsewhere, left forearm

This code signifies the death of bone tissue in the left forearm due to a disruption of blood supply, occurring as a manifestation or complication of another underlying disease process. This condition, also known as avascular necrosis, leads to bone collapse and joint destruction if untreated.

Apply this code when documentation explicitly states osteonecrosis of the left forearm and links it to a specific systemic disease (e.g., lupus, sickle cell anemia, long-term corticosteroid use, Gaucher disease). The physician's notes should clearly identify the underlying condition causing the osteonecrosis.

• Always sequence the underlying systemic disease code first, followed by this code to indicate the manifestation.
• Ensure the documentation specifies "left forearm" and not just "forearm" or "upper limb" to support this laterality.
• Distinguish from osteonecrosis due to trauma or idiopathic causes, which are coded differently.