Orthopedic Coding Alert

Get to know arthritis codes; you'll use them often for arthroplasties.

Have you ever wondered if there is a complete list of diagnosis codes that support medical necessity for all the knee arthroplasty codes?

Well, there isn't. 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 the patient's diagnosis. Also, you can check out this list of ICD-10 codes that might indicate provider performed a knee arthroplasty.

Osteoarthritis Often Plays Role in 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

RA Patients Might Need Arthroplasty

According to experts, 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 see which 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.

So be careful when coding knee arthroplasties. Choosing the correct ICD-10 code could be tricky, and you certainly don't want to mis-diagnose the patient.