Radiology Coding Alert

Five examples of what to do when the index fails you.

The transition from ICD-9 to ICD-10 marked a pivotal change in the way that we implement diagnosis codes. One of the fundamental flaws of ICD-9 was its lack of documentation of less common symptoms and diseases.

The shift to ICD-10 not only resulted in a greater specificity of codes, but also a broad increase in the overall amount diagnosis codes to choose from. However, it’s clear that even after many years of implementation, the foundation of codes ICD-10 has to offer still leaves much to be desired — including diagnostic codes that relate to diseases of the spine.

So, let’s clear the air by offering our take on which diagnoses are most applicable to those spinal diseases which can’t be traditionally found using the ICD-10 index.

General Rules to Follow

First, a disclaimer: When you cannot find a disease or symptom directly via the ICD-10 index, coders have to begin thinking outside of the “coder’s handbook” when reaching the most accurate diagnosis code possible. This means that the code you decide on might not be definitively right — but rather your best educated guess, having used all the resources at your disposal.

And the notion of utilizing “resources” is very crucial here. First and foremost, always have a medical dictionary available by your side as you work. Additionally, you will want to have access to various online sources to help guide you in the decision-making process. For radiology, you should utilize these organizations, among others:

The American College of Radiology: https://www.acr.org
Radiologyinfo.org: https://www.radiologyinfo.org
Society of Skeletal Radiology: https://www.skeletalrad.org

Code Retrolisthesis/Anterolisthesis as Spondylolisthesis

• M43.1- (Spondylolisthesis [acquired] [degenerative])

These two related diagnoses are relatively easy to understand in the grand scheme of non-indexable coding. Most coders will immediately default to code M43.1-, and in this case, they would be correct. However, this is the first of many examples in which the correct ICD-10 code does not optimally reflect the spinal condition that it is applied to.

“Anterolisthesis and retrolisthesis are conditions of the spine in which part of the vertebrae slips either forward (anterolisthesis) or backward (retrolisthesis) onto the vertebrae below,” explains Barry Rosenberg, MD, chief of radiology at United Memorial Medical Center in Batavia, New York. “Classifying these two conditions as spondylolisthesis all comes down to a matter of specificity. Anterolisthesis and retrolisthesis both fall under the spondylolisthesis family, so, despite acting as a somewhat vague descriptor, it’s perfectly appropriate to use M43.1- as a diagnosis code for these two conditions.”

Code Facet Hypertrophy as Spondylosis

• M47.- (Spondylosis)

Try indexing this particular disease. What did you find? How far in the indexing process did you get before concluding that you’re out of luck? Let’s use this diagnosis as a foundation for how to identify and apply codes to all unindexable diseases going forward:

First, we’ll look-up Hypertrophy in the index. At this point, we’ve got a broad list of anatomical locations to choose from — with Facet not being one of them. Now, we have a few different options. The first is to scour the list and find the most fitting term and go from there. However, it’s at this stage where we learn that having a fundamental knowledge of the anatomy of the codes you’re covering is crucial to any coder’s success. Some might believe that Facet is simply interchangeable with Spine. To some degree they are right, but Facet is specifically referring to the joints between each vertebra.

Without this knowledge, a coder might find themselves searching for Hypertrophy à Bone, since terms like Spine and Facet are not present under Hypertrophy. Since Facet Hypertrophy is not directly referring to bone, but rather the space in between vertebrae, this route would be incorrect.

By this stage, a coder will realize that it’s time for a little improvisation. The problem is that we don’t have a concrete grasp on what hypertrophy really means. “Facet hypertrophy is a very generalized term for the degeneration, or deterioration, of cells involving the posterior elements of the spinal canal,” Rosenberg outlines. “Numerous spinal conditions can fall under the realm of what is classified as facet hypertrophy, but the physician should always opt for a more specific diagnosis if one is available.”

With this semi-conclusive definition of hypertrophy established, we can begin to come to a more concrete answer on what code is most applicable. Heading back to the index, we find that Degeneration à Facet Joints leads us to M47.-. This is the most appropriate code to use when coding for Facet Hypertrophy.

Code Facet Arthropathy as Inflammatory Spondylopathy

• M46.9- (Unspecified inflammatory spondylopathy …)

The term Facet Arthropathy technically is indexable, but there’s been enough confusion surrounding this diagnosis that we thought it was worth including.

Now that we’ve outlined the process of converting Facet Hypertrophy into Spondylosis, finding a diagnosis for Facet Arthropathy should feel less challenging. At first, we find very little to work with in the index under Arthropathy. Our spine-related diagnoses are limited to Arthropathy à Specified Form à Bone, which we know is incorrect from the last example. Next, we try Arthritis since the index tells us that these two terms are linked.

While you won’t find Facet or Joint under Arthritis, you will find both Spine and Back as appropriate terms to lead you to the same correct diagnosis of M46.9-.

Consider These Codes, Too

Let’s review the specifics behind two additional spinal conditions that lack any clear direction from an indexing perspective.

Straightening (Spine, Cervical Lordosis):

• M53.8- (Other specified dorsopathies …)

Straightening of the spine generally refers to an acquired or congenital condition in which the natural curve of the spine straightens. This is most common in the cervical spine with a condition called straightening (or reversal) of cervical lordosis.

You won’t find the term Straightening in the index, but you will find Curvature. And in this case, straightening of the spine can be considered curvature against the spine’s natural bend. Curvature à Spine (acquired) (angular) (idiopathic) (incorrect) (postural) à Dorsopathy, deforming, at which point you will reach the correct code, M53.8-.

Remember: In most cases of ICD-10 coding, you will automatically default to “acquired” unless the term congenital (or any synonymous term) is used to document the symptom or disease.

Disc Bulge (nontraumatic):

• M50.2X, Other cervical disc displacement
• M51.2X, Other thoracic/lumbar/sacral disc displacement

Most experienced coders know to automatically apply these codes when encountering a disc bulge diagnosis, but some might be surprised to know that the term “bulge” is not documented in the ICD-10 index. As some physicians might argue that a disc bulge and disc displacement are not one in the same, we will nonetheless apply these displacement codes for lack of a better option.