Subluxation of C0/C1 cervical vertebrae, initial encounter

This diagnosis code signifies a partial dislocation or misalignment of the atlanto-occipital joint, specifically between the base of the skull (C0) and the first cervical vertebra (C1). It indicates that the joint surfaces are no longer in proper apposition but remain in partial contact, occurring for the first time.

Apply this code when documentation clearly states a subluxation of the C0/C1 joint resulting from a recent injury or trauma. Supporting documentation should include imaging reports (e.g., X-ray, CT, MRI) confirming the subluxation and a physician's note detailing the initial presentation and acute nature of the injury.

• Ensure the documentation explicitly states "subluxation" and not a complete dislocation (luxation).
• Verify that the encounter is indeed the "initial encounter" for this specific injury. Subsequent care would require a different seventh character.
• Distinguish from other cervical subluxations; this code is specific to the C0/C1 joint.