AAOS recommends 27447.22 for a conversion of a uni to total knee, but I bill 27487.52 with documentation and do not have an issue with getting Medicare to pay.I have a physician that has done what he calls a revision total knee 27487 but insurance is denying...they said there is another code when converting a unicompartmental to total. when I asked my physician to clarify his documentation he swears he revised the femoral and tibial components. however, he resurfaced the patellar which was not previously done. would you consider this a total with removal of previous prosthesis??? why or why not?