Other osteonecrosis of unspecified ulna

This code signifies the death of bone tissue in an unspecified ulna due to a loss of blood supply, not otherwise specified. It covers osteonecrosis of the ulna that doesn't fit into more specific categories like post-traumatic or drug-induced.

Apply this code when documentation clearly indicates osteonecrosis of the ulna without specifying the cause or when the cause is known but not classifiable to a more specific osteonecrosis code. This is appropriate when the laterality (left or right ulna) is not documented.

• Ensure documentation explicitly states "osteonecrosis" of the ulna.
• Avoid using this code if a more specific etiology (e.g., post-traumatic, steroid-induced) is documented; instead, use the appropriate specific code.
• If laterality is documented (left or right ulna), select the corresponding laterality-specific code instead of this unspecified code.