Neurosurgery Coding Alert

When reporting same-session arthrodesis, be careful not to mix -segments- and -interspaces-

Reporting spinal instrumentation is fairly straightforward--as long as you know the location and type of instrumentation. In part 1 of this two-part series, we discuss the first five of nine ways you can ensure accurate instrumentation coding every time.

1. Select Instrumentation Codes First by Location

When you choose CPT codes for instrumentation, location--rather than the type of device--is the most important selection criterion.

The breakdown: Instrumentation may be described as anterior (attaching to the front portion of the spine or vertebral segment, toward the -center- of the body) or posterior (attaching to the back of the spine or vertebral segment, facing toward the back), and can consist of rods, cages, plates, wires and/or other mechanical devices, says Linda Parks, MA, CPC, CMC, CMSCS, an independent coding consultant in Atlanta.

You may further classify posterior instrumentation as segmental or nonsegmental.

Tip: Generally, the type of instrumentation will correspond to the surgical approach (anterior or posterior). And the surgeon's documentation should explicitly state the type of instrumentation he places. If the surgeon's op report does not specify, be sure to ask.

2. For Posterior, Determine Segmental or Not

If the surgeon places posterior instrumentation, you must further determine if the device is segmental (22842-22844) or nonsegmental (22840). The surest way to do this is to count the number of fixation points, Parks says:

- If the surgeon attaches the instrumentation to the spine at only two points, the device is nonsegmental (regardless of the number of vertebrae spanned).

- If the surgeon attaches the device to at least three points (on three different segments), the instrumentation is segmental.

3. Only Segments Matter for Anterior Instrumentation

You should report placement of anterior instrumentation using 22845 (Anterior instrumentation; 2 to 3 vertebral segments), 22846 (- 4 to 7 vertebral segments) or 22847 (- 8 or more vertebral segments), depending on the number of vertebral segments spanned (there is no distinction between segmental and nonsegmental anterior instrumentation).

Example: The surgeon places anterior instrumentation from C6 to T3. This involves five spinal segments (C6, C7, T1, T2 and T3). Therefore, you would apply 22846.

Tip: Anterior instrumentation usually involves application of plates that the surgeon screws directly onto the vertebrae, whereas posterior instrumentation usually involves placement of rods and either hooks that grip the lamina or screws that engage the pedicles, says Gregory Przybylski, MD, director of neurosurgery at the New Jersey Neuroscience Institute, JFK Medical Center in Edison.

4. Count Levels and Interspaces Carefully

Because CPT defines codes for segmental and non-segmental (both anterior and posterior) instrumentation according to the number of vertebral segments involved (for example, 22842 specifies -... 3 to 6 vertebral segments-), you must count your vertebrae carefully.

Know your anatomy: There are seven cervical vertebrae, 12 thoracic (dorsal) vertebrae, and five lumbar vertebrae (plus the sacrum).

Possible source of confusion: Although CPT defines instrumentation procedures according to vertebral segments, it defines fusion (arthrodesis) procedures (which must accompany instrumentation claims) according to vertebral interspaces. So you must be careful to avoid confusion.

Consider this: The span T12-L4 contains five vertebral segments (T12, L1, L2, L3, L4) but only four vertebral interspaces (T12-L1, L1-L2, L2-L3, L3-L4).

Example: The surgeon performs arthrodesis at interspaces C6-C7, C7-T1 and T1-T2. The surgeon then places anterior instrumentation attached at C6 and T2.

Report 22554 (Arthrodesis, anterior interbody technique, including minimal discectomy to prepare interspace [other than for decompression]; cervical below C2) and +22585 x 2 (... each additional interspace [list separately in addition to code for primary procedure]) for the arthrodesis, and 22846 (Anterior instrumentation; 4 to 7 vertebral segments) for the instrumentation.
 
5. Look to Special Code for Cage/Other Devices

In some cases, the surgeon will place a metal cage or other prosthetic device for stabilization. This represents a third type of instrumentation, which you should report using 22851 (Application of intervertebral biomechanical device[s] [e.g., synthetic cage(s), threaded bone dowel(s), methylmethacrylate] to vertebral defect or interspace), Przybylski says.

Don't overdue it: Report only a single unit of 22851, regardless of how many devices the surgeon places at one level. If the surgeon places devices on multiple spinal levels, however, you may report multiple units of 22851 (one unit for each individual spinal level).

Example: The surgeon places two cages at level T5-6. You should claim one unit of 22851.

Alternatively, the surgeon places two cages at level T5-6 and a third cage at level T6-7. In this case, you should report 22851 x 2 units. Some payers may require you to append modifier 59 (Distinct procedural service) to the -additional- units of 22851 to distinguish them as occurring at a separate anatomic location(s). 

Next month: We discuss the final four ways to bulletproof your instrumentation claims, including complete information on reporting instrumentation removals.