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

This code describes a situation where a patient has sustained a fracture of the first metacarpal bone (thumb) in their right hand, and this fracture has failed to heal properly, resulting in a nonunion. This indicates a persistent gap or lack of bony bridging at the fracture site after the expected healing period.

This code is used for follow-up encounters when a patient is being treated for a previously diagnosed right first metacarpal fracture that has been confirmed as a nonunion. This could include visits for further evaluation, planning for surgical intervention to address the nonunion, or ongoing management of the unhealed fracture.

• Always assign an additional code to specify the underlying cause of the nonunion, if known (e.g., poor blood supply, infection).
• Ensure documentation clearly states "nonunion" and specifies the right first metacarpal bone.
• Do not use this code for initial encounters or for fractures that are still in the process of healing (malunion or routine healing).