Non-radiographic axial spondyloarthritis of thoracic region

This code describes a chronic inflammatory arthritis primarily affecting the spine and sacroiliac joints, specifically in the thoracic region, where radiographic changes characteristic of ankylosing spondylitis are not yet evident. Patients typically present with inflammatory back pain, stiffness, and reduced spinal mobility in the mid-back area.

Use this code for patients diagnosed with non-radiographic axial spondyloarthritis whose primary symptoms and objective findings localize to the thoracic spine. Documentation should clearly state "non-radiographic axial spondyloarthritis" and specify the thoracic region, often supported by clinical criteria like inflammatory back pain and elevated inflammatory markers, without definitive radiographic sacroiliitis.

• Ensure documentation explicitly states "non-radiographic" to differentiate from ankylosing spondylitis (M45.0-).
• Verify the specific spinal region (thoracic) is documented; other M45.A- codes exist for different regions.
• Consider sequencing this code as the primary diagnosis when it is the main reason for the encounter.