Osteonecrosis due to drugs, right femur

This diagnosis code signifies the death of bone tissue in the right thigh bone (femur) caused by the use of certain medications. This condition leads to bone collapse and pain, often impacting joint function. It is a serious adverse effect of drug therapy, distinct from osteonecrosis due to other etiologies.

Use this code when documentation clearly indicates avascular necrosis of the right femur and explicitly links its causation to drug therapy. Common scenarios include patients on long-term corticosteroid therapy, bisphosphonates, or certain immunosuppressants who develop femoral head osteonecrosis. Physician documentation must specify the drug etiology.

• Ensure the laterality (right femur) is clearly documented.
• Always code the drug causing the osteonecrosis as an adverse effect (T36-T50 with 5th or 6th character 5) as a secondary diagnosis.
• Distinguish from osteonecrosis due to trauma, alcoholism, or other specified causes, which have different code assignments.