# revision unicompartmental knee arthroplasty



## maryanneheath (Jul 12, 2011)

Good Morning everyone,

I have an interesting situation and was hoping for some input.  This particular patient has Medicare as primary.

My surgeon performed a revision unicompartmental knee arthroplasty, for which there is no CPT code.  There is either CPT 27446, Arthroplasty, knee, medial or lateral compartment, or 27486, Revision of TOTAL knee arthroplasty, 1 component.  I could see coding either way, with a 52 on the 27486, of course.

We are under the impression that Medicare does not accept any unlisted codes whatsoever.  How would you code in this situation?  Also, any input regarding Medicare and what to do when the CPT codes do not exactly match would be much appreciated.

Thanx, all, and have a great day!

MaryAnne


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## JMeggett (Jul 12, 2011)

Below is from the May 3, '10 OrthoCoder Pink Sheet Publication:

Question: Patient underwent a medial unicompartmental arthroplasty 19 years ago. He now presents with mechanical symptoms and pain. X-rays demonstrate poly liner completely dislodged and worn down to be bone on bone. Surgery is performed to revise the medial unicompartmental hemiarthroplasty to a total knee arthroplasty. As there is not a "conversion of previous knee surgery to a total arthroplasty" as there is for hips (27132), do we bill for removal of the previous prosthesis (27488) AND the total knee arthroplasty (27447)? What is the most appropriate way to code the procedures performed?

Answer: This question was posed recently to the AMA, which checked with the American Academy of Orthopaedic Surgeons, then responded that 27487-52 (revision of total knee arthroplasty, with or without allograft, femoral and entire tibial component) would be the most appropriate code. You should append the 52 modifier (reduced services) since the code describes revision of a total knee, but you are revising only a unicompartmental arthroplasty.

It would not be appropriate to use 27488 (removal of prosthesis, including total knee prosthesis, methylmethacrylate with or without insertion of spacer, knee) if you are putting another prosthesis in, according to the AMA.

Jenna


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