Q:  I have a physician who performed a conversion of a patellofemoral joint to a total knee. He replaced the patellar polyethylene and implanted a total knee replacement. What would be the appropriate code for this? Would this be reported as 27447 or do we need to use a revision code or the unlisted code?

A:  There isn’t a CPT code specific to conversion of a previous patellofemoral or unicompartmental arthroplasty to a total knee replacement.  The AMA and American Academy of Orthopaedic Surgeons disagree about how these procedures should be reported.

The AMA states that a partial-to-total knee conversion should be reported with 27487 (Revision of total knee arthroplasty, with or without allograft; femoral and entire tibial component) appended with modifier 52 (Reduced services). (CPT Assistant, July 2013)

Q:  I just want to make sure I understood you correctly a few minutes ago.  Patient had a medial arthroplasty done last year but now comes in for the lateral side, this is coded as just another unicompartmental with CPT 27446 correct?

A:  Yes, that is correct because it’s the opposite side of the knee.

Q:  I am new to orthopedic coding and just curious if it matters the type of implant they are using such as ceramic, metal or any other material matter when I am choosing my code?

A:  Welcome to Orthopedics!  It typically does not matter.  I say this based on today's technology, which we all know can change next week.  The only verbiage I would be concerned with is the Poly spacers which are different from the other pieces used during joint replacements.

Q:  I thought 27132 was for anything but a THA. Confused.

A: Yes, that is correct.  Looking back at the poll question, I think I should have worded that a little differently.

Q:  Is AAOS global surgery book a good reference? would you recommend it?

A:  Yes, I highly recommend using this resource to assist with orthopedic coding.