Nondisp posterior arch fx first cervcal vertebra, init

This code signifies a fracture of the posterior arch of the atlas (C1 vertebra) that has not shifted from its normal anatomical position. It specifically indicates that the fracture is closed, meaning the skin over the injury is intact, and it is the initial treatment encounter for this injury.

Apply this code when documentation clearly states a nondisplaced fracture of the posterior arch of the first cervical vertebra, such as from a hyperextension injury. This code is appropriate for the initial visit where the fracture is diagnosed and treatment begins, provided there is no open wound associated with the fracture.

• Ensure documentation specifies "nondisplaced" and "posterior arch" of C1.
• Confirm the encounter is the initial one for this specific fracture; subsequent encounters will use different seventh characters.
• Distinguish from other C1 fracture types (e.g., Jefferson fracture) which have different code assignments.