Path fracture in oth disease, l foot, subs for fx w nonunion

This diagnosis code signifies a fracture of the left foot that occurred due to an underlying disease process, not from trauma. The fracture has failed to heal properly, resulting in a nonunion, and the patient is presenting for follow-up care related to this ongoing complication.

Apply this code when documentation indicates a patient is being seen for a left foot fracture caused by a systemic condition (e.g., osteoporosis, bone tumor, metabolic bone disease) that has not united. This code is appropriate for subsequent encounters where the nonunion is the primary focus of the visit.

• Ensure documentation clearly specifies "left foot" and "nonunion" for accurate coding.
• Always sequence the underlying disease causing the pathological fracture first.
• Distinguish from malunion (M84.475K) and other types of pathological fractures without nonunion.