Coding “degenerative changes”

June 29th, 2018

Guest blog by Monita Turpin, coding analyst at 3M Health Information Systems.

*NOTE: Updates have been released on the “degenerative changes” issue in the 2nd quarter Coding Clinic. Here is a revised blog to reflect those changes.

One of the most challenging coding scenarios that I see my clients struggle with is whether or not to assign Osteoarthritis when providers document “degenerative changes” in the impression. 

Let’s walk through this coding challenge with a series of questions that will help guide us to the correct diagnosis code.

The provider documented “degenerative changes of the left knee” in the impression, and the clinical indication was left knee pain. What is the correct diagnosis code?

This scenario has caused a lot of debate among coders. According to some, it is understood that degenerative changes means osteoarthritis, but to others, the provider must specify osteoarthritis, not degenerative changes.

So, let’s go to the ICD coding book for the answer.

In the index, when we look at Degeneration, degenerative, then go to Changes, it references spine or vertebra, and instructs us to see Spondylosis. This takes us to M47 category which includes arthrosis or osteoarthritis of spine or degeneration of facet joints—not where we want to be for the knee.

Okay, let’s go back to the index.  We’re back to Degeneration, degenerative, then go to joint disease. Aha, it instructs us to see Osteoarthritis. This takes us to M17.1_, and we find M17.12—Unilateral primary osteoarthritis, left knee.

But, the provider did not specify joint disease, he only documented degenerative changes. Is M17.12 the correct code for degenerative changes of the left knee?

Back to the index again.  Let’s look at Change(s). In the index, we found joint, and we’re instructed to see Derangement, joint.  We found knee derangement in the index—M23.9 category, and our complete code is M23.92—Unspecified internal derangement of left knee. Does derangement correctly translate to degenerative changes of the knee?

What does internal joint derangement mean, and does the provider mean derangement when he documents degenerative changes? Internal joint derangement is a term used when the examiner does not have an exact diagnosis but is able to determine that something is not functioning correctly. It’s a mechanical disorder that interferes with normal joint motion or mobility.  Does this mean degenerative changes?

Degenerative joint disease (osteoarthritis), is a joint inflammation that results from cartilage degeneration. 

As coders, we cannot assume the provider’s meaning, we have to query the provider for clarification. 

Ideally, if the provider means degenerative joint disease when he documents degenerative changes of the knee, the provider should specify “Degenerative joint disease, left knee” or “DJD left knee,” or simply “Osteoarthritis, left knee” in the impression.

In the world of computer-assisted coding (CAC), we only have the provider’s documentation to auto-suggest the diagnosis code, and for CAC, the correct code is M25.562—left knee pain.

Monita Turpin is a coding analyst at 3M Health Information Systems.