Fusion of spine, thoracic region

This code describes a pathological fusion of vertebrae within the thoracic spine, meaning a natural or abnormal joining of two or more vertebral bodies. This can result from congenital anomalies, inflammatory processes like ankylosing spondylitis, or degenerative changes leading to spontaneous bony bridges. It signifies a fixed immobility in the affected segment of the thoracic spine.

Use this code when documentation clearly indicates a diagnosis of spinal fusion specifically located in the thoracic region, not due to surgical intervention. This diagnosis is often supported by imaging studies (X-rays, CT scans) showing bony ankylosis or congenital fusion. It is applicable for conditions like congenital block vertebrae or advanced stages of inflammatory arthropathies affecting the thoracic spine.

• Differentiate from post-procedural fusion (e.g., arthrodesis), which is coded differently.
• Ensure the documentation specifies "thoracic region" to avoid confusion with other spinal segments.
• Look for underlying causes (e.g., ankylosing spondylitis) which should be coded first, with this code as a secondary diagnosis.