Osteonecrosis due to previous trauma of unspecified carpus

This code signifies the death of bone tissue in an unspecified carpal bone, resulting from a prior traumatic injury. This avascular necrosis leads to bone collapse and joint degeneration within the wrist. The condition is characterized by impaired blood supply to the affected carpal bone.

Use this code when documentation explicitly states osteonecrosis of a carpal bone and attributes the cause to a previous trauma, without specifying which carpal bone is affected. Supporting documentation would include imaging reports (X-ray, MRI) confirming avascular necrosis and a clear history of prior wrist trauma.

• Ensure the documentation clearly links the osteonecrosis to a previous trauma, not an acute injury.
• Avoid this code if a specific carpal bone is identified; instead, use the more specific M87.23- subcategory codes.
• Confirm that "unspecified carpus" is documented or implied when no specific carpal bone is mentioned.