Pathological fracture, unsp foot, subs for fx w nonunion

This code signifies a fracture of an unspecified foot bone that occurred due to a pre-existing disease or condition, rather than trauma. The "subsequent encounter" indicates the patient is receiving routine care during the healing phase of the fracture, and "nonunion" specifies that the bone is failing to heal properly.

Apply this code when documentation confirms a pathological fracture of the foot, and the patient is presenting for follow-up care related to the fracture's healing, specifically when there is evidence of nonunion. This typically involves patients with underlying conditions like osteoporosis, tumors, or metabolic bone diseases.

• Ensure documentation clearly states "pathological fracture" and specifies "nonunion" for the subsequent encounter.
• Always code the underlying disease causing the pathological fracture first, if known and actively treated.
• Distinguish from malunion (M84.476P), which indicates healing in an incorrect position, rather than a complete failure to heal.