Ankylosing hyperostosis [Forestier], thoracic region

This code describes diffuse idiopathic skeletal hyperostosis (DISH), also known as Forestier's disease, specifically affecting the thoracic spine. It is characterized by ossification of ligaments and entheses, primarily along the anterior longitudinal ligament, leading to bridging osteophytes. This condition can result in spinal stiffness and reduced range of motion in the thoracic region.

Use this code when documentation confirms a diagnosis of ankylosing hyperostosis (Forestier's disease) with specific involvement of the thoracic spine. Clinical scenarios include patients presenting with thoracic back pain, stiffness, or radiographic evidence of flowing ossification along the anterior aspects of at least four contiguous vertebral bodies in the thoracic region.

• Ensure the documentation explicitly states "thoracic region" to support this specific site code.
• Do not confuse with ankylosing spondylitis (M45.-), which is an inflammatory arthropathy with different diagnostic criteria.
• Code any associated pain or neurological symptoms separately, if documented, following sequencing guidelines.