Idiopathic aseptic necrosis of unspecified shoulder

This code signifies the spontaneous death of bone tissue in the shoulder joint, not caused by infection or trauma, where the underlying reason is unknown. This condition, also known as avascular necrosis (AVN) or osteonecrosis, leads to bone collapse and subsequent arthritis if left untreated.

Apply this code when documentation clearly states "idiopathic aseptic necrosis of the shoulder" or "avascular necrosis of the shoulder of unknown etiology." This diagnosis is typically made based on imaging studies (e.g., MRI, X-ray) showing characteristic bone changes, in the absence of identifiable causes like steroid use, trauma, or sickle cell disease.

• Ensure the documentation explicitly states "idiopathic" or "unknown etiology" to differentiate from secondary causes of avascular necrosis.
• Avoid using this code if a specific cause for the aseptic necrosis is identified; instead, code the underlying condition.
• This code specifies an "unspecified shoulder." If the laterality (right or left) is documented, use the more specific codes M87.011 (right) or M87.012 (left).