Substantial growth in the development of new devices for implantation in the spine has given rise to uncertainty regarding how to appropriately code for such work. Although Current Procedural Terminology contains a variety of procedures describing use of bone, screws or prosthetic implants, it is not always evident whether existing codes can be applied to newer technology.
In CPT 2002 the American Medical Association instructed physicians not to select a code that only approximates the procedure performed but instead to report an unlisted procedure code. Therefore, neurosurgeons should use unlisted procedure codes — unless a category III code has been developed.
This Coding Corner describes category III codes and provides examples of when to use them rather than category I or unlisted codes.
Category I codes are used for procedures that have been approved by the Food and Drug Administration and that are in broad use clinically. The AMA developed category III codes as a mechanism to describe newer procedures that do not fulfill criteria for category I codes. For example, procedures using non-FDA approved devices without demonstrated clinical efficacy or broad usage may be described specifically using category III codes. Since category III codes are not valued by the Relative-Value Update Committee or reviewed by the Centers for Medicare and Medicaid Services, codes for procedures using new technology can be introduced on a semiannual basis. For example, total disc arthroplasty in the cervical and lumbar spine is described with a category III code.
However, when a procedure resembles a category I code and there is no category III code, the neurosurgeon faces a dilemma concerning the most accurate way to describe the procedure performed. The physician may also be advised by vendors concerning coding methods that do not reflect AMA policy. Two examples of such procedures include placement of intervertebral prosthetic devices (code 22851) and placement of posterior nonsegmental instrumentation (code 22840).
Code 22851 for placement of intervertebral prosthetic devices was brought before the CPT Editorial Panel in February 1995. At the time the code described placement of methylmethacrylate or metallic mesh cages into intervertebral defects. The new development of threaded titanium cages led to the revision of the code to include this additional device. The RUC subsequently valued the code using a vignette describing placement of paired threaded cages. Since the physician work consisted of either placement of pins for methylmethacrylate reconstruction or placement of instruments for insertion of a pair of threaded cages, some surgeons recommended inclusion of a threaded bone dowel, given the similarity of physician work in placement of titanium cages.
At the same CPT meeting, the vignette for placement of a bone allograft (code 20931) was reviewed. This procedure described the physician work of measuring the defect size with calipers or a trial, fashioning the bone allograft for appropriate shape and size, and then examining the graft for appropriate fit after placement. Placement of the graft was described using arthrodesis codes. Subsequent development of machined allografts created a dilemma for neurosurgeons. Although code 22851 was intended for application of prosthetic devices, it now included the example of a threaded bone dowel. However, the threaded bone dowel is “an exception” to prosthetic device usage. In contrast, the measurement and fitting of all nonthreaded machined bone should be described using category I code 20931.
Code 22840 for placement of posterior nonsegmental instrumentation was revised to describe single interspace pedicle screw fixation and transfacet screw fixation. New technology has been developed to preserve motion using pedicle screw fixation with a nonrigid material connecting the screws (e.g. Dynesis). Although some neurosurgeons have been advised by vendors to use code 22840 given the similarity in technique, that code was developed for single joint spinal fixation as an adjunct to spinal arthrodesis. Similarly, interspinous devices (such as X-stop) have been developed to limit motion without arthrodesis. Since the intent of these devices is not joint arthrodesis, these procedures are appropriately described with the unlisted code 22899.
It can be difficult for a neurosurgeon to keep up with the growing list of spinal devices being developed, and the timeline for determining and publishing clinical efficacy as well as the 18-month CPT cycle likewise makes it difficult for CPT to remain contemporary with practice. Since the AMA instructs physicians to report codes that reflect the procedure for which the code was developed, neurosurgeons are advised to use unlisted procedure codes unless a category III code has been developed as an interim step. It should be noted that payment policies remain at the discretion of the payer and that there are examples of both coverage and non-coverage decisions for category I codes, category III codes, and unlisted codes.
Gregory J. Przybylski, MD, is professor and director of neurosurgery at JFK Medical Center in Edison, N.J. He is chair of the AANS/CNS Coding and Reimbursement Committee and a member of the CMS Practicing Physicians Advisory Council, and he plans and instructs coding courses for the AANS and the North American Spine Society.