Neurosurgery Coding Alert

Open-door laminoplasties are not new, but neurosurgeons are finding new applications for these procedures. The unique nature of this surgery, as well as the lack of a specific CPT code to describe it, requires that such a service be identified by coding it with an unlisted procedure code (64999), using a modifier based on multiple procedure levels (-51), and giving special instructions and documentation to insurance carriers for consideration in the billing process.

Generally, spinal stenosis (723.0 for cervical or 724.00-724.09 for other than cervical) narrowing of the spinal canal can result in spinal cord compression, causing symptoms of pain, numbness, stiffness and loss of motor function. The standard of care for stenosis is a decompressive laminectomy (63001-63017), in which the posterior parts of the spinal canal are removed, allowing blood to flow freely to the nerves and cord, thereby restoring function. The loss of structural stability previously provided by the laminae and spinous processes, however, often results in other spinal problems, such as buckling of the spinous segments known as swan-neck deformity.

When and How to Do a Laminoplasty

According to Alfred C. Higgins, MD, a neurosurgeon with the Wenatchee Valley Clinic in Wenatchee, Wash., the open-door laminoplasty has shown to reduce these complications because it does not completely remove the lamina. Instead, they are reconstructed in a way that creates more space in the spinal canal, while maintaining structural support. This adaptation has been used widely overseas, particularly in Japan, and is now becoming more common in the United States.

The typical laminectomy (63001-63017) involves complete removal, at one or more levels, of the entire lamina from both sides of the spinous process (i.e., the palpable bumps of the backbone). By comparison, an open-door laminoplasty involves drilling through the lamina on one side and approximately 95 percent through on the other side. On lifting the open side, the remaining 5 percent of bone is fractured and then forms the hinge of the door. A small piece of bone allograft is inserted into notches carved in the open side, as if to prop the door open. Finally, the bone graft is secured in place with a titanium mini-plate. This procedure allows the larger spinal canal to take pressure off of the cord.

The retention of the posterior elements is the key benefit of the open-door technique, says Higgins. Especially in an older patient, the loss of the posterior bone structures that occur in a standard laminectomy reduces stability two ways: there is less bone to support the spine, and without the lamina to reattach the muscles to, there is less muscular support. When performed on the lumbar (lower) spine, it can preclude the need for very destabilizing facetectomies (the articulating joint of the spine) (63045-63047), which usually require a postero-lateral fusion procedure (22600-22612) at the same time to provide the needed support. The problem with any fusion performed is that the facet joints lose their ability to move, and so the patients mobility is severely curtailed. There is further risk of failure of the fusion and the possible need for re-exploration and revision in case of complication. All these complicating factors are avoided with the open-door approach.

How to Code This Multi-level Procedure

Higgins notes that this technique does require more skill, as well as additional work, so coding and billing for the procedure requires special attention. Eric Sandham, CPC, compliance educator for Central California Faculty Medical Group, a group practice and training facility associated with the University of California at San Francisco in Fresno, and a coder who specializes in neurological procedures, notes that physicians performing this procedure inadvertently may cheat themselves out of optimum reimbursement if they code open-door laminoplasties as if they were typical laminectomies (63001-63015). Some have suggested using these laminectomy codes with the -22 modifier (unusual procedural services), but Sandham disagrees.

Using the laminectomy codes as a baseline for determining payment for laminoplasties makes it unlikely neurosurgeons will get the proper evaluation and individual consideration these procedures deserve, says Sandham. Further, laminoplasties usually are done at multiple levels, and the decompressive laminectomy codes bundle three or more levels into a single code. Because of the careful and extensive work involved, each additional level deserves additional payment.

Sandham recommends using code 64999 (unlisted procedure, nervous system) for each level at which a laminoplasty is performed, appending the -51 modifier (multiple procedures) for additional levels beyond the initial level. This will generally take longer for the payment to be adjusted and will require submission of the operative note, but for this particular procedure I feel the benefits outweigh the drawbacks.

Support Your Coding With a Procedural Letter

Getting a claims adjuster to determine a fair reimbursement for the procedure will require a hands-on approach. First of all, notes Sandham, the operative report must reflect the additional work and effort involved as much as possible. The more detailed the dictation, the better. Our experts recommend writing a separate letter, and attaching it to the claim to indicate the following:

Meticulous drilling involved in maintaining the 5 percent hinge;
Creation of notch on the open side of the door for insertion of bone graft;
Shaping and insertion of bone graft;
Attachment of titanium plate(s);
Reattachment of muscles;
Foraminotomy, if performed; and
Additional levels at which laminoplasty was performed.

Show a Procedural Comparison

Provide some guidance to help the claims adjuster or medical director come to a fair reimbursement amount. As far as the basic work is involved, it would be logical to compare each level of open door laminoplasty to a single level of laminectomy (63001-63015) and a single level of fusion (22600-22614), given that the lamina is all but removed, and that a bone plug is inserted and secured. Knowing how this procedure compares to similar procedures, and how it differs, will help neurosurgeons and their staff to know whether to appeal any payment determination received. Finally, the structural allograft deserves separate billing using code 20931 (allograft for spine surgery only; structural).

With research showing the efficacy of open-door laminoplasties, and more of them being performed, it is essential to educate payers as to the unique nature of the procedures. As for a new code to describe them, Sandham has submitted a sample operative report to the CPT Editorial Board for their consideration and hopes that a future revision of CPT will have a new code so that such analoguing to other codes will be unnecessary.