Neurosurgery Coding Alert

If spinal bone graft coding has you stymied, your road to success is as easy as learning basic terminology and focusing on where your surgeon obtains the material he will use. Answer these three questions, and you'll choose every spinal graft code with confidence.

The surgeon can harvest bone from the patient's own body to graft onto the spine or he can use bone from a human donor. If he uses the patient's own bone, you'll code for an autograft (auto = "self") using one of the following codes:

• +20936 -- Autograft for spine surgery only (includes harvesting the graft); local (e.g., ribs, spinous process, or laminar fragments) obtained from same incision (List separately in addition to code for primary procedure)

• +20937 -- ... morselized (through separate skin or fascial incision) (List separately in addition to code for primary procedure)

• +20938 -- ... structural, bicortical or tricortical (through separate skin or fascial incision) (List separately in addition to code for primary procedure).

Example: The surgeon removes a portion of bone from the patient's rib through the same thoracic spinal exposure site, reshapes the bone as necessary, and grafts it onto the spine for reconstruction. You'll report +20936 in addition to the primary surgical procedure code, says Rena G. Hall, CPC, a coder and auditor with KC Neurosurgery Group in Kansas City, Mo.

Bone for an allograft, by contrast, comes from a human donor (either a living donor or a cadaver) for use in a different human recipient (allo = "other"). Allografts also include synthetic applications. When reporting allograft procedures, choose between two codes:

• +20930 -- Allograft for spine surgery only; morselized (List separately in addition to code for primary procedure)

• +20931 -- ... structural (List separately in addition to code for primary procedure).

Documentation clues: Your surgeon's documentation can provide clues to the type of procedure he performed.

In the case of an allograft, the surgeon does not harvest the bone (although he might shape the bone prior to placing it). Instead, he receives the previously harvested allograft from a surgical or regional bone bank prior to the surgery.

Tip: If your neurosurgeon's documentation mentions that the bone came from a bone bank, that means you'll code for an allograft.

If you determine that the surgeon obtained an autograft, your next step is to verify whether he made single or multiple incisions to harvest the bone and place the graft.

Option 1: If the surgeon harvests and places the bone via the same skin and fascial incision, you'll go straight to +20936.

Option 2: If the surgeon harvests and removes the bone through a skin or fascial incision, then makes a second, separate incision to place the bone onto the spine, you'll choose another autograft code instead, says Deborah Messinger, CPC, a coding specialist with Massachusetts General Physicians Organization in Charlestown. You have one more question to answer, however, before you can complete the claim.

For all allograft procedures (and for any autograft your surgeon does not harvest and place via the same incision), you must verify whether the graft is structural or morselized. Documentation of "structural" versus "morselized" grafts should be easy to find in the operative report.

Definitions: A structural bone graft consists of a single piece of bone that provides direct support for skeletal structures. Watch for key words such as "shaped" or descriptions of "graft size" to know you're dealing with a structural graft, Hall says.

A morselized (or small-segment) graft consists of several smaller pieces of bone packed together to fill bony cavities, primarily to promote new bone growth. "A key word here would be 'mixed,'" Hall says.

Once again, knowing whether the bone is an autograft or allograft will guide your final coding choice. For a structural autograft, you should select +20938. For a structural allograft, choose +20931.

For a morselized autograft, the appropriate code is either +20937 or +20936, depending on whether the surgeon acquired the bone from the same incision or made a new one. For a morselized allograft, turn to +20930.

Example 1: The neurosurgeon performs anterior interbody fusion at that level with minimal discectomy (without decompression), and places a Cornerstone fibular allograft and plate for a patient with C5-C6 degenerative cervical disc disease (722.4, Degeneration of cervical intervertebral disc). Report +20931 for the Cornerstone allograft (in addition to the codes for arthrodesis).

Example 2: The surgeon performs a posterior lumbar interbody fusion for stenosis (724.02, Spinal stenosis; lumbar region) and spondylolisthesis (738.4, Acquired spondylolisthesis) at L2-L3 and L3-L4. He harvests bone from the iliac crest, via a separate incision, to prepare and place a morselized graft at each interspace. He fixes pedicle screws at two points (L2 and L4) to stabilize the spine further. You'll report the harvest and grafting with +20937, plus codes for arthrodesis and instrumentation.

Remember that autograft codes are specifically designed to include graft harvesting, Hall says. CPT does not contain a separate code to report the shaping of bone for use in spinal grafts, although all spinal grafting codes (+20930 - +20938) include graft shaping or preparation. Allograft codes do not include harvesting because the surgeon obtains the bone from a bone bank rather than from the patient's own body. Because allografts do not include harvesting, they pay slightly less than otherwise similar autograft procedures.

Note: Medicare applies zero relative value units (RVUs) for +20930 and +20936. Other payers may have a fee schedule for these codes, however. "You may or may not receive reimbursement for these two services," Hall says, "but that doesn't mean you shouldn't bill them."