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

This code signifies a fracture of the third metacarpal bone in the left hand where the specific type of fracture (e.g., transverse, oblique) is not documented. Importantly, it indicates that the fracture has failed to heal properly after an initial treatment, and the patient is presenting for ongoing management of this nonunion.

This code is appropriate for follow-up encounters when a patient with a previously treated, but unspecified, left third metacarpal fracture is diagnosed with nonunion. It should be used when the patient is receiving active treatment for the nonunion, such as surgical intervention, bone grafting, or continued conservative management.

• Ensure documentation clearly states "nonunion" and specifies the left third metacarpal.
• Verify that the encounter is for active treatment of the nonunion, not just routine follow-up of a healed fracture.
• Always sequence this code after the primary reason for the encounter, if applicable.