October 2004 Bulletin

Coding spinal procedures: Part II

More tips to reduce confusion

By Margie Scalley Vaught, CPC, CPC-H, CCS-P, ACS-OR; Blair C. Filler, MD, and M. Bradford Henley, MD

The last “Coding Corner” discussed three of the five basic items that must be documented and supported when selecting the appropriate codes for spinal procedures. This column will address the remaining two items: spinal instrumentation (rods, screws or cages) and bone grafting (allograft or autograft).


The key elements that must be provided for spinal instrumentation procedures are the approach, the number of segments and the type of instrumentation placed.

Spinal instrumentation codes fall into several categories, depending on where and how the instrumentation is implanted. Spinal instrumentation may be inserted anteriorly (22845-22847) or posteriorly (22840, 22842-22844). There are many different configurations of spinal instrumentation, including wiring (22841), nonsegmental fixation (22840), segmental fixation (22842-22844), fixation to the pelvis, and application of intervertebral biomechanical device(s) (22851).

Segmental fixation is “defined as fixation at each end of the construct and at least one additional interposed bony attachment.” The nonsegmental code is “defined as fixation at each end of the construct and may span several vertebral segments without attachment to the intervening segments.”

According to the CPT Manual, “A vertebral segment describes the basic constituent part into which the spine may be divided. It represents a single complete vertebral bone with its associated articular processes and laminae.” If the surgeon documents that posterior instrumentation, segmental was applied for levels T4-T8, the appropriate code would be 22842, “Posterior segmental instrumentation (eg, pedicle fixation, dual rods with multiple hooks and sublaminal wires); 3 to 6 vertebral segments.” In this case, five vertebral segments (T4-T8) are included in that description. If the surgeon states that anterior instrumentation was placed from T2-T10, the appropriate code would be 22847, “Anterior instrumentation; 8 or more vertebral segments,” because T2-T10 includes nine vertebral segments.

CPT code 22841 is problematic. In the February 1996 CPT Assistant, the AMA stated, “Code 22841 describes internal fixation, such as spinous process wiring and spinous process plating. Do not report this code when wiring is performed with other types of segmental or non-segmental instrumentation. Minimal wiring is considered an inclusive component of segmental and non-segmental instrumentation codes.” This code would be reported just one time during an operative session. However, according to the Federal Register, the RVU for this code is zero (0).

One spinal instrumentation code that continues to cause reporting problems is code 22851, “Application of intervertebral biomechanical device(s) (eg, synthetic cage(s), threaded bone dowel(s), methylmethacrylate) to vertebral defect or interspace.” The September 1997 CPT Assistant states that “CPT code 22851 is not intended to be reported per cage. CPT code 22851 should only be reported one time, regardless if one or more metal cages are placed in the intervertebral space at the same level. However, if metal cages are placed at two different levels, (eg, 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. It is important to note that a single cage or methylmethacrylate can cover a defect of several vertebral segments (eg, a single cage may replace three entire vertebrae), wherein code 22851 would still only be reported one time.”

The same article goes on to explain, “If metal cages are placed through an anterior approach and pedicle screws are placed through a posterior approach, it would be appropriate to report both code 22851 and one of the codes from the posterior instrumentation series, 22840, 22842-22844. However, if different instrumentation is used in addition to the metal cages or methylmethacrylate through the same approach (eg, an anterior plating system) or pedicle screws and posterior lumbar interbody fusion utilizing cages, then the appropriate instrumentation code would be reported in addition to code 22851. However, 22851 and 22845 should not both be reported if only the metal cage is inserted.”

Many spinal devices have come out causing further confusion as to whether or not they can be considered as ‘cages.’ ‘Interbody fusion devices,’ for example, are not considered as cages under the definition used by the American Medical Association, the North American Spine Society (NASS) and the AAOS. These groups define a cage as a ‘threaded cylindrical bone dowel.’ The use of interbody fusion devices will fall under more of the spinal grafting codes than under instrumentation codes.


Spinal bone grafting has taken on a life of its own over the last several years. Medicare has not helped the issue by bundling several of the grafting codes, such as 20930 and 20936, and assigning them both zero (0) RVUs. CPT has also weighed in on the description of bone grafting and how many times a bone graft code can be reported during a given procedure.

The December 1999 CPT Assistant states “Code 20937 is to be reported only one time for the procedure, regardless of the number of vertebral levels being surgically fused.” This reference first appeared in 1996 when the codes came out with the following disclaimer “Codes 20930-20938, although appearing under the heading of General Musculoskeletal Procedures, apply only to bone grafts used for spine surgery. It is important to note that only the bone graft procedure code is reported once per operative session.”1

Depending on the situation, two different types of bone grafting may be reportable, as shown in a clinical example in the May/June 2004 CPT Assistant supplement.

The spinal grafting codes are defined based on whether the graft is an allograft or an autograft, whether it is morselized or structural, and whether it was obtained through the same incision or a separate incision. Codes 20930 and 20931 are both for allograft material, whether morselized or structural. Codes 20936-20938 are for autografts. Use code 20936 when the graft is obtained through the same incision. Use code 20937 when the graft is morselized through a separate skin or fascial incision. Use code 20938 when the graft is a structural, bicortical or tricortical graft obtained through a separate skin or fascial incision.

The spinal graft codes in the CPT Manual reference CPT code 38220, “Bone marrow; aspiration only.” This code can be reported only ONCE, no matter how many aspirations are done. Both the AAOS and NASS caution surgeons that this code should not be used if the “aspirate” is taken from the same site/exposure of an autograft harvest. It should not be used if the aspirate is done through an exposure for harvesting other graft such as 20937 or 20938.

Just as different devices for spinal instrumentation have been developed, you will find that there are different types of bone grafting material. Always verify that the product will meet the CPT description before seeking additional reimbursement. If you are approached about using a product, make sure that the product information has been submitted to the AAOS Coding Committee and CPT Coding Committee to ensure it meets a given CPT code.2

Always document

Documentation is key to supporting the reporting of both the instrumentation and grafting codes. Clear wording and descriptions should be supported in the body of the operative note. If the procedure involves harvesting an autograft, make sure that the note reflects both the harvesting and the placement. Use words such as “graft was placed in XXX” or “grafting material was applied to XXX.” Avoid words such as “shored up” or “reinforced” without further elaboration because they may not provide clear documentation of bone grafting. When documenting instrumentation, be clear about where the instrumentation starts, where it ends and how it was applied.


  1. CPT Assistant, February 1996 Vol. 6, Issue 2
  2. http://www.usdoj.gov/usao/cac/pr2003/158.html

Margie Scalley Vaught, CPC, CCS-P, CPC-H, ACS-OR, is an independent coding specialist in Ellensburg, Wash. A BONES member, she has served as a member of the National Advisory Board for the American Academy of Professional Coders. She can be reached at vaught@kvalley.com

Blair C. Filler, MD, is a member of the AAOS CPT-ICD Coding Committee. He can be reached at bcfiller@umich.edu

M. Bradford Henley, MD, is professor of orthopaedic surgery at the University of Washington and a member of the AAOS CPT-ICD Coding Committee. He can be reached at bhenley@u.washington.edu

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