Displ longitud fx left patella, subs for clos fx w nonunion

This code signifies a fracture running lengthwise through the left kneecap that is no longer in its proper anatomical alignment. Crucially, this fracture has failed to heal adequately and is being treated during a follow-up visit, with the skin over the fracture remaining intact.

Apply this code for patients presenting for ongoing management of a previously diagnosed displaced longitudinal fracture of the left patella where imaging confirms nonunion. This is appropriate for follow-up appointments, cast changes, or evaluations for further intervention (e.g., surgery) for the unhealed fracture.

• Ensure documentation specifies "left" patella and "longitudinal" fracture type.
• Verify the encounter is for subsequent care and that nonunion is explicitly documented.
• Confirm the fracture is closed; open fractures would require a different code.