Ankylosing spondylitis of thoracolumbar region

This code identifies a chronic inflammatory arthropathy primarily affecting the axial skeleton, specifically localized to the thoracic and lumbar spine. It is characterized by progressive stiffness and pain in the thoracolumbar region due to inflammation of the sacroiliac joints and spine, potentially leading to spinal fusion.

Apply this code when documentation explicitly states a diagnosis of ankylosing spondylitis with the primary or most significant involvement noted in the thoracolumbar spinal segments. Supporting documentation should include physician notes detailing symptoms like back pain, stiffness, and imaging findings consistent with ankylosing spondylitis in this specific region.

• Ensure the documentation specifies "thoracolumbar region" to differentiate from other spinal segments.
• Do not use if the ankylosing spondylitis is generalized or affects only cervical or sacral regions; more specific codes exist for those presentations.
• Consider sequencing this code as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis when it is a comorbidity affecting treatment.