Other secondary osteonecrosis of left ulna

This code signifies the death of bone tissue in the left ulna due to an underlying medical condition or external factor, rather than a primary, idiopathic cause. This osteonecrosis is not spontaneous but rather a consequence of another disease process, trauma, or medication.

Apply this code when documentation specifies osteonecrosis of the left ulna and clearly indicates a secondary etiology, such as corticosteroid use, systemic lupus erythematosus, sickle cell disease, or a history of radiation therapy. It is appropriate when the provider explicitly states "secondary osteonecrosis" or provides a definitive link to an underlying cause.

• Ensure the documentation specifies "secondary" osteonecrosis; otherwise, consider M87.135 (idiopathic) or M87.235 (drug-induced).
• Always code the underlying cause of the secondary osteonecrosis first, if known and applicable, following ICD-10-CM sequencing guidelines.
• Verify laterality is clearly documented as "left ulna" to avoid miscoding to the right or unspecified ulna.