Displaced lateral mass fx first cervcal vertebra, sequela

This code signifies a long-term complication or late effect resulting from a previous fracture of the lateral mass of the first cervical vertebra (atlas), where the bone fragments were displaced at the time of the initial injury. It indicates that the patient is experiencing ongoing issues directly attributable to this past fracture, such as chronic pain, instability, or neurological deficits.

Apply this code when documenting a patient presenting with a current condition or symptom that is a direct consequence of a previously healed or treated displaced lateral mass fracture of the C1 vertebra. Documentation should clearly link the current problem to the old injury, often through phrases like "due to prior C1 fracture" or "sequela of remote atlas fracture." This code is appropriate for follow-up care related to the long-term effects, not the initial acute injury.

• Always use a sequela code as a secondary diagnosis, following the code for the specific current condition or symptom being treated (e.g., chronic pain, cervical myelopathy).
• Ensure the medical record explicitly states that the current condition is a sequela or late effect of the past fracture, rather than an acute or subsequent injury.
• Distinguish from codes for acute fractures (S12.040A-D) or nonunion/malunion (M84.28, M84.38, M84.48), which describe different stages or complications.