Disp fx of nk of 1st MC bone, r hand, subs for fx w malunion

This code signifies a right-hand first metacarpal neck fracture that was initially displaced but has now healed incorrectly, resulting in malunion. The patient is presenting for follow-up care related to this improperly healed fracture.

Apply this code when documenting a subsequent encounter for a patient with a previously diagnosed displaced fracture of the right thumb metacarpal neck, and clinical or radiological findings confirm malunion. This would be used when the patient is receiving treatment or evaluation for the complications arising from the malunion, such as pain or functional impairment.

• Ensure documentation clearly states "malunion" and specifies the "right hand" and "first metacarpal neck."
• Verify that this is a subsequent encounter, not the initial treatment for the fracture.
• Distinguish from nonunion, which indicates a complete failure of bone healing.