Spondylolysis, occipito-atlanto-axial region

This code describes a defect or stress fracture in the pars interarticularis of the vertebrae specifically located in the occipito-atlanto-axial region (C0-C2). This condition can lead to instability and pain in the upper cervical spine.

Apply this code when documentation clearly indicates spondylolysis affecting the junction between the skull and the first two cervical vertebrae. This diagnosis is often supported by imaging studies such as X-rays, CT scans, or MRI showing the pars defect.

• Ensure the documentation specifies the occipito-atlanto-axial region; do not use for spondylolysis in other spinal segments.
• Distinguish from spondylolisthesis, which involves anterior displacement of one vertebra over another, though spondylolysis can be a precursor.
• Look for associated symptoms like neck pain, stiffness, or neurological deficits, which may require additional codes.