Neurosurgery Coding Alert

Follow these rules when the ICD-10 index fails you.

The implementation of ICD-10, while stressful at the time, was an important step in giving coders the opportunity to apply diagnosis codes to diseases and symptoms that were previously unindexable with ICD-9.

However, after a couple years of implementation, it’s clear that ICD-10 still leaves much to be desired — specifically when it comes coding to diseases of the spine. So, let’s clear the air by offering our take on which diagnoses are most applicable to spinal diseases that you cannot correlate with the ICD-10 code book.

Disclaimer:

Remember, when you cannot directly find a disease via the ICD-10 index, coders have to begin thinking outside of the “coder’s handbook” when reaching the most accurate diagnosis. 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. Your best bet is to confer with your provider and colleagues to create some universal rules to follow when you come across particular diagnoses that can’t be found in the index.

Here’s a few resources to fall back on when you find yourself in one of these coding predicaments:

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

Use this Advice to Code Retrolisthesis/Anterolisthesis

These two sibling diagnoses are relatively easy in the grand scheme of non-indexable coding. Most coders will immediately default to code M43.1X (Spondylolisthesis), and in this case, they would be correct. However, this is the first of many examples we will come across in which the documented diagnosis and the ICD-10 diagnosis are not necessarily one in the same.

“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 are both classified 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.”

It is important to note, however, that these two conditions have different physiological and treatment implications, despite having the same diagnostic code.

Dig Deep for Accuracy on Facet Hypertrophy

Try indexing Facet Hypertrophy in ICD-10. 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 the term Facet is simply interchangeable with Spine. To some degree they are right, but Facet is specifically referring to the joints between each vertebrae.

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.- (Spondylosis). This is the most appropriate code to use when coding for Facet Hypertrophy.

Go This Route for Facet Arthropathy

The term Facet Arthropathy is technically 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. We first find very little to work with under Arthropathy in the index. 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 M46.9X (Unspecified inflammatory spondylopathy).

Consider a Few More Diagnoses

Here are a few more conditions that might twist your brain while you’re searching for the correct diagnosis:

Straightening (Spine, Cervical Lordosis)

• M53.8-, Other specified dorsopathies

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 all 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, thoracolumbar, and lumbosacral intervertebral disc displacement

Most experienced coders know to automatically apply these codes when the physician documents a disc bulge, but some might be surprised to know that the ICD-10 index does not list “bulge” as an indexable term 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.