Other secondary osteonecrosis of unspecified ulna

This code describes the death of bone tissue in an unspecified ulna due to a secondary cause other than trauma, infection, or specific diseases like Caisson disease or hemoglobinopathy. This condition can lead to pain, joint dysfunction, and potential collapse of the affected bone.

Assign this code when documentation specifies osteonecrosis of the ulna as secondary to a systemic condition, medication use (e.g., corticosteroids), or other non-traumatic, non-infectious etiologies, and the specific ulna (left or right) is not documented. Supporting documentation should clearly indicate the secondary nature of the osteonecrosis and the affected bone.

• Ensure documentation specifies "secondary" osteonecrosis and rules out primary or other specified secondary causes.
• Avoid using this code if the laterality (left or right ulna) is clearly documented; instead, use the more specific code.
• Always sequence this code after the underlying condition causing the secondary osteonecrosis, if applicable.