Unsp physl fx low end ulna, unsp arm, subs for fx w nonunion

This code signifies a follow-up encounter for a growth plate fracture at the lower end of the ulna (forearm bone) where the fracture has not healed properly (nonunion). The specific arm affected is not documented.

This code is appropriate for subsequent visits when a patient is being managed for a previously diagnosed, unhealed physeal fracture of the distal ulna. It indicates that the fracture has failed to unite and further treatment or monitoring for this complication is ongoing.

• Requires a seventh character of "K" for subsequent encounter with nonunion.
• Ensure documentation clearly states nonunion of the fracture.
• If the arm (left or right) is specified, a more specific code should be used.