SRS Newsletter
March 2012
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Coding for Deformity Combined with Degenerative Stenosis: A Case Example

Patrick Cahill

Patrick Cahill, MD
Coding Committee Member

Spinal deformity surgery and spinal surgery for degenerative conditions are not mutually exclusive fields. If a Venn diagram were used to describe the two fields, there would be significant overlap. Even on the level of a single patient, degenerative and deforming processes may be contributing to pathology. ICD-9, however, attempts to stratify and codify surgical procedures into one category or the other. This can be confusing for surgeons and those coding their procedures. This article will attempt to provide some guidance in surgical coding in cases where the distinction between degenerative and deformity conditions is blurry.

The overriding principle should be correct coding rather than maximizing reimbursement. The surgeon should decide the primary indication(s) for performing a specific procedure and select the code or codes for that procedure. For example, if a surgeon removes the facet joints and ligamentum flavum at a lumbar level on which she or he is operating to increase flexibility and improve correction, then the procedure should be coded as a single column posterior osteotomy (22214). However, if the structures were removed for bilateral foraminal stenosis and/or neural compression then the procedure should be billed as a decompressive procedure (63047).

The case below illustrates some of the principles of correct coding where a combination of degenerative stenosis and deformity exist. The patient is a middle aged gentleman with a degenerative spondylolisthesis fused at L4-5, then later extended to L3-4, who developed sagittal imbalance after discitis destroyed the L2-3 disc space. The pre-operational CT-myelogram shows severe stenosis at L2-3 and moderate stenosis at L1-2. The surgeon performed an L4 pedicle subtraction osteotomy (PSO), L1-pelvis posterior instrumented spinal fusion, with laminectomies from L1-3. The patient had pathology related to deformity and degenerative issues-focal kyphosis resulting in global sagittal imbalance as well as symptomatic stenosis. The surgeon performed a surgery to address these issues. The PSO and instrumentation treated the deformity and the decompression treated the stenosis.

Thus, the surgery combines several individual components: arthrodesis, removal of instrumentation, insertion of instrumentation (to pelvis), decompression, osteotomy, and insertions of allograft and locally obtained autograft.

The deformity correction is addressed by several codes including 22800 (posterior arthrodesis for deformity up to six segments), 22207 (three column lumbar osteotomy), 22842 (three to six segment lumbar instrumentation), 22848 (pelvic instrumentation), 20936 (locally harvested autograft), and 20930 (allograft). The surgeon selected these codes based on the indications and goals of the specific procedures.

Note that the arthrodesis codes are stand-alone codes, which mean that they are 90-day global codes which can be coded and billed in isolation and include pre-operative evaluation and post-operative care. Several of the other codes, (instrumentation and allograft) are add-on codes and cannot be billed in isolation. Interestingly, while it is appropriate to bill for the bone graft codes 20930 and 20936, neither is assigned any work value by Medicare, although some private payers may reimburse for this procedure. Note that even though the original instrumentation is removed, it is not appropriate to code for this procedure as it is presumed by payers to be included in the insertion procedure, according to CPT rules. This is supported by an update for CPT coding issued in February 2012 by the American Academy of Orthopaedic Surgeons (AAOS) stating:

"Guideline changes also address removal of instrumentation and insertion of new instrumentation, including all or part of the previously instrumented segments as well as reinsertion at the same level. In years past, the surgeon reported the removal of old hardware (22850,22852,22855) and also reported the placement of new hardware when the procedures were performed at different levels.

Beginning in 2012, if a new surgeon removes instrumentation at L3-L4 and inserts new instrumentation from L1 through L5, only the new instrumentation codes should be reported---not codes for both the removal of the old instrumentation and the insertion of the new instrumentation. If the surgeon removes old instrumentation."

Instrumentation to the pelvis should only be coded if the instrumentation extends to the ilium. Instrumentation to the sacrum alone does not merit use of this code. The osteotomy code 22207 is also a stand-alone code and is actually valued more than the arthrodesis code 22800, so would be listed first and the 22800 would be listed subsequently and appended by the -51 modifier so as to avoid billing again for pre- and post-operational work.

The decompression codes 63047 (lumbar laminectomy and facetectomy with foraminal decompression) and 63048 (additional level) were selected to describe the laminectomy procedures since the primary indication was decompression of neurologic structures and not malalignment or instability. 63047 is a stand-alone code, but since it is done in conjunction with the arthrodesis and osteotomy procedures and is valued less, it is appended with the -51 modifier to avoid billing again for pre- and post-op work. 63048 is an add-on code and needs no modifier.

Each of the stand-alone codes must be supported by a diagnosis from ICD-9. The arthrodesis and the osteotomy codes can be justified by 737.10, Kyphosis (acquired) (postural), or 737.41 - Kyphosis. The decompression codes can be justified by 724.02, spinal stenosis, lumbar region without neurogenic claudication or 724.03 with claudication.

Unlike surgical procedures performed in other regions of the body, spine surgeries often require several codes to properly describe what is actually done. A good working knowledge of the codes and their proper interactions is needed to accurate document and bill for the performed services.

Pre- and Post-op images

Pre- (left) and Post- (right) op images of an adult male who underwent a revision surgery for sagittal imbalance and stenosis.

Thanks to Anthony Rinella, MD and Wendy Benefeldt of Illinois Spine & Scoliosis Center and Jacob Buchowski, MD of Washington University, in assisting with the preparation of this article.

Chairman: R. Dale Blasier, MD Committee Members: Jeffrey B. Neustadt, MD, Kern Singh, MD, Brandon J. Kambach, MD; Patrick Cahill, MD, Christopher DeWald, MD; Michael P. Chapman, MD, Mathew D. Hepler, MD.