Path fx in oth disease, l ankle, subs for fx w nonunion

This code signifies a fracture of the left ankle that occurred due to an underlying disease process, rather than trauma. It indicates that the patient is receiving ongoing treatment for this pathological fracture, and the fracture has not healed properly, resulting in a nonunion.

Apply this code when a patient presents for follow-up care of a left ankle pathological fracture, and documentation explicitly states the fracture has not united. This code is appropriate for subsequent encounters where nonunion is being managed, such as for surgical intervention to promote healing or continued conservative management.

• Ensure documentation clearly specifies "left ankle" and "nonunion" in the context of a pathological fracture.
• Always code the underlying disease causing the pathological fracture first, followed by this code.
• Distinguish from malunion (M84.472K) or routine healing encounters (M84.672D, M84.672P).