Unsp fx left patella, subs for opn fx type 3A/B/C w nonunion

This code describes a situation where a patient has an unspecified fracture of the left kneecap that has failed to heal properly (nonunion). This particular nonunion is occurring after an initial open fracture of a severe nature (Type IIIA, IIIB, or IIIC).

Use this code for follow-up encounters when a patient is receiving ongoing treatment for a nonunion of an unspecified left patellar fracture. The original injury must have been a severe open fracture (Gustilo-Anderson Type IIIA, IIIB, or IIIC). This code would be appropriate for monitoring healing, managing complications, or planning further interventions for the nonunion.

• Always sequence this code after the appropriate external cause code, if applicable, for the original injury.
• Ensure documentation clearly specifies "nonunion" and the left side, along with the history of a severe open fracture type.
• Do not use this code for initial encounters or for malunion; a different code would be required.