Idiopathic aseptic necrosis of left carpus

This code signifies the spontaneous death of bone tissue in the left carpal bones due to an interruption of blood supply, without an identifiable cause such as trauma, infection, or systemic disease. It results in bone collapse, pain, and functional impairment of the wrist.

Apply this code when documentation explicitly states idiopathic avascular necrosis (AVN) or osteonecrosis affecting the left carpus. This diagnosis is typically supported by imaging studies (e.g., MRI, X-ray) showing characteristic bone changes and the exclusion of secondary causes.

• Ensure laterality (left) is clearly documented and matches the code.
• Distinguish from traumatic avascular necrosis, which would be coded differently.
• Verify that "idiopathic" or "aseptic" is specified; otherwise, investigate for a secondary cause.