Neurosurgery Coding Alert

Hint: Streamline coding by counting interspaces and not devices.

You can avoid spinal cage coding traps if you readjust your focus on interspaces rather than on devices used. Free up payment for your spinal cage procedures with the following guidance.

Keep a Count on Interspaces

You report 22851 (Application of intervertebral biomechanical device[s] [e.g., synthetic cage[s], methylmethacrylate] to vertebral defect or interspace [List separately in addition to code for primary procedure]) once per interspace or defect and not the number of spinal cage devices. The descriptor also mentions ‘device(s)’ which implies you can submit the code for one or more devices that your surgeon places.

What is a spinal interspace? A spinal or vertebral interspace is the non-bony compartment between two adjacent vertebral bodies. This is also referred to as the ‘intervertebral disc.’ The components of spinal interspace are nucleus pulposus, annulus fibrosus, and two cartilaginous endplates.

Example: If you read that your surgeon placed three cages at interspace T11/T12, you should report only a single unit of 22851. This is because your surgeon is working only on a single interspace.

You can report additional units of 22851 for additional interspaces if your surgeon works on more than one.

Example: If you read that your surgeon placed two cages at T11/T12 and a third cage at T12/L1, you may report 22851 x 2.

Don’t forget: “In order for the carrier to understand that you have placed the additional cage at a different anatomical interspace/defect, you should report the second device (22851) with the 59 modifier,” says Gregory Przybylski, MD, director of neurosurgery, New Jersey Neuroscience Institute, JFK Medical Center, Edison.

Caveat: When your surgeon performs discectomy, with or without decompression, at more than one continuous interspace, you should count the numbers of intervertebral defects. In such a situation, you report one unit of 22851 for every intervertebral defect in which your surgeon places the cage or prosthetic device. “However, if the defect created from decompression includes two adjacent intervertebral discs and the intervening vertebral body, one would still only report a single unit of an interverterbral prosthetic device,” says Przybylski.

Example: You may read that your surgeon did a corpectomy at T9 and then did a fusion at interspaces T7-8, T8-9, and T9-10 with a intervertebral cage at T7-8 and an expandable cage to bridge the corpectomy defect between T8-9 and T9-10 with anterolateral instrumentation using vertebral screws and rods.

The operative note may read that the T9 vertebral body was removed piecemeal using sharp curettes and rongeurs as it was found to be completely disintegrated and soft.

Further in the operative note, you may read “Continuous neuromonitoring was done to verify cage placement and staples were applied to T8 and T7 vertebral bodies and screws were placed through the staples. Singular staples were placed in the T10 vertebral body, trying to avoid existing pedicle screws, placing the screws in lower end of the vertebral body in the endplate neighborhood.”

What to code: In this scenario, there is a single defect between the T8 and T10 vertebral bodies (after resection of the T9 vertebral body and adjacent T8-9 and T9-10 discs). You report only a single unit of 22851 for the placement of the single interbody expandable cage that your surgeon is doing. “You would then report a second unit of 22851 appended with the 59 modifier for placement of the second intervertebral prosthetic device at the T7-8 defect,” says Przybylski.

Make Sure You Report the Primary Procedure

Because code 22851 is an add-on code, you report it in addition to the code(s) for the primary procedure(s). Your surgeon may remove a portion of the vertebra and then use a metal cage or other prosthetic device to stabilize the area. You would report this with code 22851 in addition to the code for the primary procedure.

Example: You may read that in a patient with L4-5 mobile degenerative spondylolisthesis and intractable back pain, your surgeon did a posterior L4-5 interbody arthrodesis with an interbody cage placement along with a posterolateral arthrodesis.

In this case, you report 22633 (Arthrodesis, combined posterior or posterolateral technique with posterior interbody technique including laminectomy and/or discectomy sufficient to prepare interspace [other than for decompression], single interspace and segment; lumbar) for the primary procedure, and 22851 for the spinal cage.

“In keeping with a recent trend toward rebundling services, the previously separate procedures of posterior interbody fusion 22630 and posterolateral fusion 22612 are now reported with the single code 22633 when performed concurrently at the same interspace level,” says Przybylski.

Cover All Applicable Devices

The code descriptor for 22851 mentions ‘application of biomechanical device(s)’ and you can further read some examples, i.e. ‘synthetic cage(s), methylmethacrylate.’ Remember that these are only a few examples and do not mean that the code is restricted to only a synthetic cage or methylmethacrylate.

“While the device may be made from a number of various synthetic materials such as titanium, carbon fiber, polyethylethylene ketone, a machined bone allograft is not considered a prosthetic cage. In fact, the threaded bone dowel was removed from the parenthetical list of examples to clarify that code 22851 should not be applied to bone allograft,” says Przybylski.

Instead, you may report code 20931 for bone allografts that are available in a variety of shapes and sizes. Such allografts may be pieces of fibula that are shaped and prepared to promote bone growth and hence fusion. Another type of graft that qualifies for 20931 may be a piece of cortical bone surrounding trabecular bone that is held by metal pins and shaped for insertion between two vertebral segments.

Tip: Turn to 22851 when you confirm in the operative note that your surgeon used a “non-bony” prosthetic device or 20931 when your surgeon used a structural ‘fibular allograft bone plug or bone spacer.’

Check with Payers for Modifiers

Do check with your payer to verify that you should append modifier 59 (Distinct procedural service) to the second unit of 22851. Some payers allow the 59 modifier with the second unit of 22851 to indicate that the instrumentation was placed at a separate anatomic location.

Note: Also, ensure that your surgeon documents that the cages or other prosthetic devices were placed in different interspaces.

Report Cage Replacement as Reinsertion

You can consider spinal cage replacement as reinsertion of any spinal fixation device. The best approach for a cage replacement is to select a reinsertion code.

Example: You may read that a patient who had direct lateral interbody fusion and intervertebral cage placement with bone grafting in the past reported to your surgeon after a fall, and your surgeon confirmed a displaced cage. Your surgeon in this case may decide to extrude the displaced cage and replace it with another cage.

In this instance, you could report the new cage placement including removal with 22851 alone, but it would be more accurate to report this as a reinsertion of a spinal fixation device and submit code 22849 (Reinsertion of spinal fixation device). “Keep in mind that code 22849, unlike most of the other spinal instrumentation codes, is a stand-alone code rather than an add-on code and is subject to the multiple procedure rule,” says Przybylski.