Oth fx first MC bone, left hand, subs for fx w nonunion

This code signifies a fracture of the first metacarpal bone in the left hand, excluding Bennett's or Rolando's fractures, that has failed to heal properly. The patient is currently receiving care for this unhealed fracture, indicating an ongoing treatment phase for the nonunion.

Apply this code when documenting a patient presenting for follow-up care, evaluation, or treatment of a previously diagnosed, non-healing fracture of the left thumb's metacarpal bone. This includes scenarios such as cast changes, physical therapy for nonunion, or surgical planning for revision.

• Ensure documentation clearly specifies "nonunion" and the "left hand" for the first metacarpal.
• Confirm this is a subsequent encounter, not the initial treatment for the fracture.
• Distinguish from Bennett's or Rolando's fractures, which have specific codes.