Neurosurgery Coding Alert

Eradicate same-session arthrodesis errors by not mixing -segments- with -interspaces.-

You can obliterate spinal instrumentation coding errors as long as you know the location and type of instrumentation. Face these five myths to discover the coding realities.

Myth #1: When coding instrumentation, you need to know the type of device before anything else.

Reality: When you choose CPT codes for instrumentation, location -- rather than the type of device -- is the most important selection criterion. -I would first look at the approach: anterior versus posterior,- confirms Rebecca Woodward, CPC, coding representative for MedVentures, LLC in High Point, N.C.

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 Lawrenceville, Ga.

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.

Myth #2: You determined the surgeon places posterior instrumentation, and soyou have all you need to determine what code to use.

Reality: Posterior instrumentation means you must further determine if the device is segmental (+22842-+22844) or non-segmental (+22840). Parks says the surest way to do this is to count the number of fixation points:

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

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

Myth #3: You determined the surgeon places anterior instrumentation, and so you have to figure out whether the device is segmental or non-segmental to appropriately code this service.

Reality: 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. These codes show no distinction between segmental and non-segmental 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.

Helpful: 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.

Myth #4: Because you-ve determined anterior/posterior and non-segmental/segmental, you don't need to count vertebrae.

Reality: 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.

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

Hidden trap: Although CPT defines instrumentation procedures according to vertebral segments, it defines fusion (arthrodesis) procedures (which typically must accompany instrumentation claims) according to vertebral interspaces. So you must be careful to avoid confusion. For instance, 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.

Myth #5: You don't have any other types of instrumentation.

Reality: 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.

Warning: Report only a single unit of +22851, regardless of how many devices the surgeon places at one intervertebral defect. If the surgeon places devices on multiple spinal levels, however, you may report multiple units of +22851 (one unit for each individual intervertebral defect).

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- unit(s) of +22851 to distinguish them as occurring at a separate anatomic location(s).