Idiopathic aseptic necrosis of left shoulder

This code signifies the death of bone tissue in the left shoulder joint due to a lack of blood supply, without an identifiable cause such as trauma or infection. This condition, also known as avascular necrosis (AVN) or osteonecrosis, leads to bone collapse and subsequent arthritis.

Apply this code when documentation explicitly states idiopathic avascular necrosis affecting the left humerus head or other bones of the left shoulder. Supporting documentation typically includes imaging reports (MRI, X-ray) confirming osteonecrosis and clinical notes ruling out secondary causes.

• Ensure documentation specifies "idiopathic" or "primary" to differentiate from secondary AVN.
• Verify laterality (left shoulder) is clearly documented; separate codes exist for right and bilateral involvement.
• Do not confuse with osteomyelitis or other forms of bone necrosis with an identified cause.