Orthopedic Coding Alert

Total knee replacement takes center stage with these codes.

When your orthopedist performs a knee arthroplasty, picking the proper code can leave even the most seasoned coder dizzy with choices.

After all, there are at least eight codes you might consider when the provider performs knee arthroplasty. To code correctly, you need to know the anatomy and totality of the arthroplasty; some knee arthroplasties are complete, while some only address certain areas of the knee.

Help's here: Read this FAQ for guidance on some of the most common questions coders consider when reporting knee arthroplasty procedures.

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: How would a total knee replacement clinical scenario play out?

A: Before the orthopedist opts for knee replacement, she might try to alleviate the patient's pain through less drastic measures. According to Paige, "Most patients undergo several attempts at conservative management prior to undergoing a knee replacement."

These management attempts might include, but are not limited to: patient weight loss plan, physical therapy, and "cortisone injections and other injections into the joint for viscosupplementation: Hyalgan, Synvisc," saysPaige.

Once the orthopedist decides to perform a total knee arthroplasty, the encounter might look like this:

A patient has a diagnosis of primary osteoarthritis in his left knee. Past management techniques included: both cortisone and viscosupplementation injections; physical therapy (PT); and a weight-loss plan. Still, the patient is suffering from the condition, and reports severe pain when walking and often at night, even when he is not walking. X-rays and a magnetic resonance imaging (MRI) show bone on bone in the knee joint.

Op notes indicate that the orthopedist performed a knee arthroplasty, in which he cut the bone to remove the distal femur and proximal tibia. The orthopedist then replaced the distal femur and proximal tibia with artificial components.

This is an example of a total knee arthroplasty. On the claim, you'd report 27447 with M17.12 (Unilateral primary osteoarthritis, left knee) appended to prove medical necessity.