Path fx in oth disease, unsp humerus, subs for fx w nonunion

This code signifies a pathological fracture of an unspecified humerus that has failed to heal properly (nonunion) and is being treated in a subsequent encounter. The fracture occurred due to an underlying disease process, not trauma.

Apply this code for patients presenting for follow-up care, cast changes, or continued treatment of a humerus fracture that developed due to a systemic condition (e.g., osteoporosis, metastatic cancer) and has been documented as nonunion. Documentation must clearly state the pathological nature of the fracture, the anatomical site, and the nonunion status.

• Always sequence the underlying disease causing the pathological fracture first.
• Ensure documentation specifies "nonunion" for accurate code assignment; malunion would require a different code.
• Verify the encounter type is "subsequent" for ongoing care of the fracture.