Unsp fx lower end of l humerus, subs for fx w malunion

This code signifies an unspecified fracture of the lower portion of the left humerus that is currently undergoing treatment for malunion. Malunion indicates that the fracture has healed, but in an unsatisfactory or deformed position, which may lead to functional impairment.

Apply this code when documenting a patient's follow-up visit for a previously sustained, unspecified fracture of the distal left humerus that has healed incorrectly. This is appropriate when the malunion itself is the focus of the current encounter, such as for evaluation, planning for corrective surgery, or managing ongoing symptoms related to the deformity.

• Ensure documentation clearly specifies "malunion" and the "subsequent encounter" status for the fracture.
• Always verify laterality (left humerus) is explicitly stated in the medical record.
• This code requires an additional code to specify the type of malunion if known (e.g., M84.4x- for malunion of fracture).