Neurosurgery Coding Alert

In the February 2005 CPT Assistant, the American Medical Association clarified that the only allograft that qualifies for code +22851 (Application of intervertebral biomechanical device[s] [e.g., synthetic cage(s), threaded bone dowel(s), methylmethacrylate] to vertebral defect or interspace) is the threaded-bone dowel. You may also apply 22851 for intervertebral devices made of PEEK or metal.

Important: You can report 22851 once for each level. But 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 three bone dowels at interspace T11-T12, you should report 22851 just once.

You may report additional units of 22851 for additional interspaces the neurosurgeon treats, however. The September 1997 CPT Assistant states, -If metal cages are placed at two different levels, (e.g., metal cage placed at L3-4 interspace and L5-S1 interspace), then 22851 may be reported more than once to indicate that one or more cages were placed at two or more different levels.- But the AMA cautions, -It is important to note that a single cage or methylmethacrylate can cover a defect of several vertebral segments (e.g., a single cage may replace three entire vertebrae), wherein code 22851 would still only be reported one time.-

For example, if the surgeon places two bone dowels at T11-T12 and a third dowel at T12-L1, 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 instrument-ation placed at a separate anatomic location.

For all other, nonthreaded machined bone (such as Cornerstone graft, VG2 graft, etc.) you should report +20931 (Allograft for spine surgery only; structural), the September 1997 CPT Assistant says.