Question: If the surgeon performs a total knee replacement (TKR) but during surgery decides the new knee is unstable and performs a TKR revision during the same session, may I report both the TKR and the revision? Kansas Subscriber Answer: No. If the surgeon performs a TKR and revision in the same session, you should only report one successful knee replacement: 27447 (Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing [total knee arthroplasty]). Timing matters: If the surgeon performs a TKR revision after the initial TKR's global period, you should report one of the following codes: - 27486 -- Revision of total knee arthroplasty, with or without allograft; one component - 27487 -- - femoral and entire tibial component. Example: The surgeon performed a unicondylar knee replacement three years ago, but it failed and the patient required a new TKR. The orthopedist removed the unicondylar and replaced it with a TKR. You should report 27487 for this service because the surgeon replaced the old knee replacement with a total knee replacement.