Nondisp lateral mass fx 1st cervcal vert, 7thK

This code describes a fracture of the lateral mass of the C1 vertebra that is not displaced, meaning the bone fragments are still in their normal anatomical position. The "subsequent encounter" indicates the patient is receiving routine care during the healing phase of the fracture, and "nonunion" specifies that the fracture has failed to heal completely after an appropriate period.

Use this code for follow-up visits where a patient is being treated for a previously diagnosed, nondisplaced lateral mass fracture of the atlas (C1) that has not united. Documentation should clearly state the fracture is of the lateral mass, nondisplaced, and that nonunion is present, along with the encounter being for ongoing fracture care.

• Ensure documentation specifies "lateral mass" and "nondisplaced" for C1.
• The "K" seventh character indicates nonunion, differentiating it from routine healing (D) or delayed healing (P).
• Do not use for initial treatment or for malunion; separate codes exist for those scenarios.