Neurosurgery Coding Alert

Question: Our neurosurgeon used "Abbott" allograft bone for an anterior cervical discectomy and fusion (ACDF). I would code it as +20931 (Allograft for spine surgery only; structural ...), but he believes we should use +22851 (Application of intervertebral biomechanical device[s] [e.g., synthetic cage(s), threaded bone dowel(s), methylmethacrylate] to vertebral defect or interspace ...). He explains: "It is two separate pieces that the physician separately mills and contours. Afterward, the doctor glues them together to form a combination cortical/cancellous device. This device has a consistent size and strength rather than a piece of tricortical bone from a cadaver, which has inconsistent size and strength. A factory does this. The physician does the piece of tricortical iliac crest at the time of surgery. Thus, the milled biomechanical device comes that way." Who is correct?

Washington Subscriber

Answer: You are. According to the American Association of Neurological Surgeons (AANS), all allograft bone other than a threaded allograft bone dowel is coded as +20931. You should use +22851 when your physician uses a synthetic device.

Keep in mind: If your physician uses a synthetic device or threaded bone dowel, you can report +22851 once for each level. Even if the neurosurgeon places more than one threaded bone dowel at a particular level, you should still report the code just once for that interspace. For instance, if the surgeon places two cages or two bone dowels at interspace L4/L5, you should report a single unit of +22851.

You may report additional units of +22851 for additional interspaces the neurosurgeon treats. For example, if the surgeon places two cages at L4/L5 and a third cage at L5/S1, you should report +22851 x 2.

Tip: For some payers, you may have to append modifier 59 (Distinct procedural service) to the second unit of +22851 to indicate that it represents instrumentation placed at a separate anatomic location.