Osteonecrosis due to drugs of left ulna

This diagnosis code signifies the death of bone tissue in the left ulna 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 potential joint destruction.

Apply this code when documentation clearly states osteonecrosis of the left ulna and explicitly links it to drug therapy (e.g., corticosteroids, bisphosphonates). Supporting documentation should include imaging reports (MRI, X-ray) confirming osteonecrosis and a detailed patient history outlining medication use.

• Ensure the laterality (left) and specific bone (ulna) are clearly documented.
• Verify that the physician explicitly states the drug-induced etiology; otherwise, a different osteonecrosis code may be more appropriate.
• Sequence this code as a primary diagnosis when the osteonecrosis is the main reason for the encounter, or as a secondary diagnosis if it's a co-morbidity.