Lumbar Spinal Fusion

Most coders have probably noticed a rise in the number of spinal fusions being performed. The number is growing extremely fast. It’s hard to get an exact number as the statistics are not for our current year. One study showed about 118% increase in the number of spinal fusions in the United States between the years 1998 and 2014. It will be interesting to see the new studies once they are completed. We have likely passed the 500,000 mark for spinal fusions in the United States by 2022.

Let’s first look at what a fusion is: A fusion is performed to fuse together (think of this as welding together) the two bones/vertebrae so that when it heals it is one single solid bone. Any two or more vertebrae in the spine can be fused together. This will prevent movement which will prevent pain if it all goes as planned.

There are many types of lumbar fusions that are performed on patients. Most Common are:

• PLIF-Posterolateral interbody fusion (#1 performed)
• TLIF-Transforaminal interbody fusion
• DLIF-Direct lateral lumbar interbody fusion
• ALIF-Anterior lumbar interbody fusion
• OLIF-Oblique lateral interbody fusion 

The decision on which one will be done depends on a few things: 

• Overall general health of the patient and body size/shape
• Which bones will be fused together?
• What is the diagnosis for the need for the fusion?
• Surgeon preference and expertise

In the distant past, when an anterior and posterior fusion were performed at the same time, this required turning of the patient which was called a 360-degree spinal fusion. With improved surgical technology and instruments, this is often done via one incision without the need to turn the patient. To report an anterior and posterior fusion were performed together, a physician must document that there was bone grafting at the anterior and posterior sites. Without the use of bone graft, this would not be coded as a fusion.

Posterolateral Lumbar Interbody Spinal Fusion (PLIF):

Since the most common spinal fusion in the US is the PLIF, let’s look at what this means. Since it is the most performed, the surgeons are very familiar with and well trained on completing these fusions. The physician will have better visualization for other procedures needed during the fusion such as any decompressions. With this approach, there is option for the 360-degree single incision fusion (this is also possible in the TLIF).

In the PLIF, the surgeon will approach the vertebrae via the back (posterior). There may be need for decompression, diskectomy, or other procedures at the time of the fusion. These will be completed, and the surgeon will place bone graft material over the transverse processes of the site that will need to be fused. Sometimes the coders will see the surgeon describe placing the bone graft in the “posterior or posterolateral gutters” which are the transvers process portion of the vertebra. Often, the use of screws and rods are used to help stabilize the spine as the bone graft/fusion is being achieved.

It sounds like this would be very easy to code. But we find these being missed often. The posterior portion of the fusion is left off when there is also an anterior fusion completed. This is a very significant coding miss and does impact the facility reimbursement by tens of thousands of dollars.

What can coders look for?

• Anytime you have an operative note with the term “interbody” look for documentation of a posterior lumbar fusion site. These are oftentimes done with anterior fusion via the same incision. We see that the anterior is being coded but the posterior is being left off.
• Search your fusion operative note for the term “facet joint” to see if this was packed with bone graft.
• Search your fusion operative note for the term “gutter” to see if the gutters were packed with bone graft.
• When vertebrae are decorticated and filled with autograft/allograft material in the gutters it is considered a posterior fusion.
• When facet joint is decorticated and autograft/allograft material is packed, this is considered a posterior fusion.

During the research on spinal fusions, I did find a few interesting facts to share:

• About 20% of spinal fusion surgeries result in failed back syndrome
• The more vertebrae that are fused the higher the chance of failure in the fusion
• The first spinal fusion performed was in 1911
• Spinal fusions were done first to treat tuberculosis or deformities
• The most common diagnosis for lumbar fusion is lumbar degenerative disc disease
• The most common diagnosis for cervical fusion is disc displacement
• No approach for lumbar fusion is superior to another and it is based on surgeon preference
• Thoracic fusions are performed the least
• There are over a million spinal surgeries per year in the US and the most common is lumbar fusion
• Most patients in the US having spinal fusions are on Medicare

Coders should review the entire operative note to ensure that all procedures are reported. Remember, coding changes are costly to the facility with the review and rebilling process. Best practice is to code it right from the start.

Authored by Kim Boy, RHIT, CDIP, CCS, CCS-P

References
https://www.beckersspine.com/spine/45273-surgeons-perform-1-62m-instrumented-spinal-fusions-per-year-in-the-us-5-things-to-know
https://www.frontiersin.org/articles/10.3389/fpain.2022.856252
https://orthoinfo.aaos.org/en/treatment/posterolateral-lumbar-fusion
https://regenerativespineandjoint.com/2019/02/14/limitations-on-mobility-after-spinal-fusion
https://www.mayoclinic.org/tests-procedures/spinal-fusion/about/pac-20384523
https://orthoinfo.aaos.org/en/treatment/posterolateral-lumbar-fusion
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7797794/
https://orthoexperts.com/most-common-types-of-spine-surgery/
https://midamericaortho.com/blog/272-4-facts-about-spinal-fusion

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Coding Clinic, First Quarter 2019 Page: 22
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ICD-10-PCS Official Guidelines for Coding and Reporting (B3.10C)

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