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

This code signifies a fracture of the first metacarpal bone (thumb) in the left hand that has not healed properly after an initial treatment. The patient is presenting for follow-up care related to this persistent nonunion. This indicates a complication in the healing process of the original fracture.

Use this code for patients who are receiving ongoing medical care, such as cast changes, physical therapy, or surgical planning, for a left first metacarpal fracture that has been diagnosed as a nonunion. This applies when the initial treatment has failed to achieve bone healing and further intervention is required.

• Ensure documentation clearly states "nonunion" and specifies the left first metacarpal.
• Verify this is a "subsequent encounter," meaning the patient is past the initial acute treatment phase.
• Do not use for initial fracture treatment or for malunion, which is a different healing complication.