Outpatient Facility Coding Alert

27447 leaves the IPO List in 2018. Here's what outpatient coders need to know.

The 2018 Outpatient Prospective Payment System (OPPS) proposed rule removes total knee arthroplasty (CPT^®  27447) from the inpatient-only list. If the final rule confirms TKA's removal from the IPO list, ambulatory surgical centers and hospital outpatient departments will have a significant new revenue stream. TKA could hit Addendum AA-the ASC-payable list-as soon as Jan. 1, 2019.

Total joint replacements offer "explosive" new growth opportunities for ASCs in the coming years, remarked Michael Patterson, FACHE, CEO of Mississippi Valley Surgery Center. (Patterson and billing office manager Kristine Stark were presenters at this year's Ambulatory Surgery Center Association Meeting in Washington, D.C.) By 2025, outpatient total knee replacement will account for 20 percent of all TKRs performed, Patterson and Stark noted, citing Sg2 data.

Performing total joint replacements in outpatient settings also benefits patients, Patterson and Stark pointed out. The cost will be 20-30 percent less than inpatient procedures, the risk of infection will decrease, and recovery will occur at home rather than in the hospital, which many patients prefer.

Outpatient coders will need to know more about knee arthroplasties in the coming years, so we've got a FAQ to help your business office code and bill correctly.

Q: What is the most common type of knee arthroplasty procedure?

A: The most common type of knee arthroplasty is 27447 (Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing (total knee arthroplasty)), which represents standard total knee replacement, confirms Bill Mallon, MD, former medical director of Triangle Orthopedic Associates in Durham, N.C.

There are, however, quite a few different knee arthroplasty codes in the CPT^® book, including:

• 27437 - Arthroplasty, patella; without prosthesis
• 27438 - ... with prosthesis
• 27440 - Arthroplasty, knee, tibial plateau
• 27441 - ... with debridement and partial synovectomy
• 27442 - Arthroplasty, femoral condyles or tibial plateau(s), knee
• 27443 - ... with debridement and partial synovectomy
• 27445 - Arthroplasty, knee, hinge prosthesis (eg, Walldius type)
• 27446 - ... medial OR lateral compartment.

The above-listed codes are for arthroplastic knee surgery variants, but your provider will perform 27447 most often, Mallon explains. Other experts, such as Heidi Stout, BA, CPC, COSC, PCS, CCS-P, with Coder on Call, Inc., in Milltown, New Jersey, say you might see a few 27438 and 27446 claims as well, but orthopedists rarely perform procedures represented by the other arthroplasty codes.

Best bet: If you see evidence of one of the lesser-known knee arthroplasty procedures in an operative report and you aren't sure which code to choose, ask your supervisor or the provider which arthroplasty code you should report.

Q: How can a coder identify a total knee replacement?

A: A total knee replacement involves both a femoral component and a tibial component. In some cases, the orthopedist also replaces the patella, explains Lynn M. Anderanin, CPC, CPMA, CPPM, CPC-I, COSC, senior director of coding education at Healthcare Information Services in Park Ridge, Ill. So, keep your eyes open for a potential 27447 claim if you see clues on femoral and tibial components in the operative report.

According to Denise Paige, CPC, COSC,  an orthopedic coder with Bright Health Physicians, Whittier, California, sniffing out a 27447 claim could be easy. "The first place to look would be in the title of the operative report," she says, as the title might provide clues as to the procedure type.

Mallon concurs with this strategy. In his experience, "the op note or encounter form will almost always say 'total knee replacement' or 'total knee arthroplasty'" for 27447 claims.

Drill deeper: If the op report title doesn't contain any revelatory information, Paige says she "would look in the body of the report, specifically for bone cuts to remove the distal femur and proximal tibia and placement of components to replace them. That way I know it's a total knee [replacement], not a partial replacement," Paige explains.

Q: Which ICD-10 codes support medical necessity for knee arthroplasties?

While 27437 (Arthroplasty, patella; without prosthesis) through 27447 (Arthroplasty, knee, condyle and plateau; medial AND lateral compartments with or without patella resurfacing (total knee arthroplasty)) share a common root, they don't share a common list of acceptable diagnoses across procedures and payers.

Don't fret: If the operative report isn't clear, you can always ask your provider to confirm the patient's diagnosis. Also, you can check out this list of ICD-10 codes that might indicate the provider performed a knee arthroplasty.

Experts agree that most of the knee arthroplasty claims orthopedic coders see will involve some sort of arthritis, most likely osteoarthritis. Some knee-related ICD-10 codes include:

• M17.0- (Bilateral primary osteoarthritis of knee)
• M17.1- (Unilateral primary osteoarthritis of knee)
• M17.2- (Bilateral post-traumatic osteoarthritis of knee)
• M17.3- (Unilateral post-traumatic osteoarthritis of knee)
• M17.4- (Other bilateral secondary osteoarthritis of knee)
• M17.5- (Other unilateral secondary osteoarthritis of knee)
• M17.9- (Osteoarthritis of knee, unspecified)

Another patient population that often requires knee arthroplasties are patients with rheumatoid arthritis (RA). Some knee-related RA ICD-10 codes include:

• M05.06- (Felty's syndrome, knee)
• M05.16- (Rheumatoid lung disease with rheumatoid arthritis of knee)
• M05.26- (Rheumatoid vasculitis with rheumatoid arthritis of knee)
• M05.36- (Rheumatoid heart disease with rheumatoid arthritis of knee)
• M05.46- (Rheumatoid myopathy with rheumatoid arthritis of knee)
• M05.56- (Rheumatoid polyneuropathy with rheumatoid arthritis of knee)
• M05.66- (Rheumatoid arthritis of knee with involvement of other organs and systems).

In addition to the M05.06- code set, ICD-10 also lists several more diagnosis categories for different types of rheumatoid arthritis (RA): RA with involvement of other organs or systems, RA with rheumatoid factor, etc. Each of these RA code sets includes a diagnosis for RA of the knee.

Remember to Check Payer Policies

The above ICD-10 codes are merely examples of diagnoses you might report along with a knee arthroplasty. As always, you should only report codes based on hard evidence you see in the operative report. Also, you'll need to check your payer contracts to seewhich diagnoses each one accepts for knee arthroplasty.

The acceptable ICD-10 codes for knee arthroplasty will vary by payer, or course, as well as by the type of procedure - medically acceptable diagnoses for the 27437-27447 arthroplasties will likely vary depending on the operative notes.

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