Fracture of unsp phalanx of thmb, subs for fx w malunion

This code signifies a fracture of any phalanx (proximal or distal) of an unspecified thumb, where the initial healing process has resulted in an unsatisfactory alignment of the bone fragments. This malunion indicates that the fracture has healed, but in a deformed or misaligned position.

This code is appropriate for encounters where a patient is being treated for complications arising from a previously sustained, unspecified thumb phalanx fracture that has healed incorrectly. This includes follow-up visits for assessment of the malunion, planning for corrective surgery, or managing ongoing symptoms related to the malaligned healing.

• Ensure documentation clearly specifies "malunion" and not "nonunion" (which has a different code category).
• Verify that the encounter is for a subsequent visit related to the fracture's healing, not the initial treatment.
• Confirm the fracture location is an unspecified phalanx of the thumb; avoid using this code if a specific phalanx (e.g., proximal) is documented.