Flail chest, subsequent encounter for fracture with nonunion

This code signifies a flail chest injury that is currently being treated for a fracture that has not healed properly. A flail chest occurs when a segment of the rib cage breaks and detaches from the rest of the chest wall, often due to multiple rib fractures, leading to paradoxical movement during respiration. The "nonunion" aspect indicates that the fractured ribs are failing to mend together after a typical healing period.

Use this code for patients presenting for ongoing management of a flail chest where the primary concern is the lack of healing of the underlying rib fractures. This would apply to follow-up visits, hospital admissions for surgical intervention for nonunion, or other treatments aimed at promoting bone healing after the initial injury has passed its acute phase.

• Ensure documentation clearly states "flail chest" and specifies that the encounter is for "nonunion" of the fractures, not just a routine follow-up for a healed fracture.
• Always sequence this code after the appropriate external cause code if the cause of the original injury is still relevant and being treated.
• Verify the encounter is indeed "subsequent" and not an initial encounter for a newly diagnosed flail chest or an acute exacerbation.