Osteonecrosis in diseases classd elswhr, unsp upper arm

This code signifies the death of bone tissue in an unspecified upper arm, resulting from an underlying medical condition. This osteonecrosis is not primary but secondary to another disease process, leading to bone infarction and potential collapse.

Apply this code when documentation clearly indicates osteonecrosis of the upper arm (humerus) and specifies that it is a manifestation or complication of another classified disease, but the specific arm (left or right) is not documented. Supporting documentation includes imaging reports (MRI, X-ray) confirming osteonecrosis and physician notes linking it to an underlying systemic condition.

• Always sequence the underlying disease code first, as this code represents a manifestation.
• Avoid using this code if the laterality (left or right upper arm) is specified; use the more specific M90.521 or M90.522.
• Ensure the documentation explicitly states "in diseases classified elsewhere" to differentiate from primary osteonecrosis.