Fusion of spine, cervicothoracic region

This code describes the pathological joining or growing together of vertebrae in the cervicothoracic region of the spine. This fusion can be congenital, developmental, or acquired due to disease processes or trauma, resulting in reduced mobility and potential neurological compromise.

Assign this code when documentation specifies a diagnosis of natural or pathological fusion occurring specifically between the cervical and thoracic vertebrae. This is distinct from surgical fusion and should be supported by imaging reports (e.g., X-ray, CT, MRI) or clinical notes detailing the anatomical location of the fusion.

• Differentiate from surgical arthrodesis (Z98.1), which is a post-procedural state, not a pathological fusion.
• Specify the exact vertebral levels if documented, using more precise codes within the M43.2- category when available.
• Code any associated neurological deficits or pain conditions separately, as this code describes the anatomical anomaly.