Oth nondisplaced dens fracture, subs for fx w nonunion

This code signifies a fracture of the dens (odontoid process) of the C2 vertebra that is not displaced, meaning the bone fragments remain in their normal anatomical alignment. The "subsequent encounter" indicates the patient is receiving follow-up care for this fracture, and "nonunion" specifies that the bone is failing to heal properly after the expected healing period.

Apply this code when a patient presents for ongoing management of a previously diagnosed, nondisplaced dens fracture that has not united. Documentation should clearly state "nonunion" or "failed healing" of the dens fracture, along with the nondisplaced nature. This code is appropriate for office visits, hospital encounters, or other services related to addressing the nonunion.

• Ensure documentation explicitly states "nondisplaced" and "nonunion" for the dens fracture.
• Distinguish from malunion (S12.121M), where the fracture has healed in an incorrect anatomical position.
• Always sequence this code as a primary diagnosis when the nonunion is the focus of the encounter.