Neurosurgery Coding Alert

Question: How can I determine segmental from nonsegmental spinal instrumentation?

North Dakota Subscriber

Answer: For posterior instrumentation to determine if the device is segmental (+22842-+22844) or nonsegmental (+22840, Posterior non-segmental instrumentation [e.g., Harrington rod technique, pedicle fixation across one interspace, atlantoaxial transarticular screw fixation, sublaminar wiring at C1, facet screw fixation ...), count the number of fixation points:

- 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.

In some cases, the surgeon will place a metal cage or other prosthetic device for stabilization in an area where he has removed a large portion of the vertebra. 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 ...).

Be careful: 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.

Example: The surgeon places two cages at level T6. Report +22851 x 1.

Alternatively, the surgeon places two cages at level T6 and a third cage at level T8. Report +22851 x 2. 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).