Monteggia's fx unsp ulna, subs for clos fx w nonunion

This code signifies a Monteggia's fracture, a specific type of forearm injury involving a fracture of the ulna combined with a dislocation of the radial head, affecting an unspecified side. The "subsequent encounter" indicates that the patient is receiving ongoing care for this injury, and "nonunion" specifies that the fractured bone fragments have failed to heal together after a typical healing period.

This code is appropriate for follow-up visits where a patient with a previously diagnosed Monteggia's fracture of an unspecified ulna is being managed for a closed fracture that has not united. This includes scenarios such as cast changes, physical therapy evaluations, or surgical planning for nonunion repair, provided the fracture was initially closed.

• Ensure documentation clearly states "nonunion" for the ulna fracture component of the Monteggia's injury.
• Verify that the encounter is for subsequent care, not the initial treatment of the fracture.
• Confirm that the laterality of the ulna fracture (left or right) is not specified in the medical record.