Orthopedic Coding Alert

This month, we will analyze a spinal surgery that includes arthrodesis (fusion), diskectomy, and instrumentation. This case was submitted for study because many of the procedures had been denied when submitted to the insurance company.

Procedure: Reconstruction of L1 vertebral body, spine fusion with autogenous grafting and instrumentation for scoliosis.

Diagnosis: Malunited fracture, L1, idiopathic scoliosis.

Codes billed: 22810, 63077, 22222, 22846, 20936, 22226, 22226, 22226 and 20937.

Operative procedures: The patient was placed on the left side in preparation for an anterior approach. The abdomen was entered at the area of the ninth rib.

The initial graft was obtained (20936, autograft for spine surgery only [includes harvesting the graft]; local [ribs, spinous process, or laminar fragments] obtained from the same incision). The ninth rib was removed and retained for grafting material during the arthrodesis. The vertebral bodies between T11 and L3 were exposed.

The old tissue from the previous fracture was removed and the vertebral bodies reshaped where necessary: (22222, osteotomy of spine, including diskectomy, anterior approach, single vertebral segment; thoracic and 22226, each additional vertebral segment [List separately in addition to code for primary procedure]).

The disk spaces of T11-T12, T-12-L1, L1-L2, L2-L3 were excised with a combination of sharp blade dissection, curettes, and rongeurs, exposing the cancellous and cortical surfaces of the endplates. The body of L1 was seen to contain a 1.4-cm to 2.0-cm irregular oval-shaped defect in its proximal surface and a little bit on its caudad surface, where scar tissue from the old fracture was present. This tissue was removed leaving a small defect. There was no nonunion but there was substantial soft tissue defect. The cortical rim was intact. The vertebra were somewhat wedge-shaped.

Next, the fusion was accomplished and the instrumentation placed for stability (22810, arthrodesis, anterior, for spinal deformity, with or without cast, 4 to 7 vertebral segments and 22846, anterior instrumentation; 4 to 7 vertebral segments).

After all the disks were removed and the endplates exposed, the ninth rib was cut up into small pieces. The instrumentation was then placed using premeasured Moss-Miami screws inserted through the bodies of L3, L2, L1, T11, and T12. A rod was contoured, inserted in the screw heads and fastened with the fastening screws. The rod was rotated and locked into place. The endplates were fish-scaled prior to putting in the bone graft, and then the bone graft was placed into the prepared endplate disk spaces. Beginning at L2-L3, the disk space was closed after it had been packed with bone by compressing the screws and locking. The same procedure was done up to T11-T12. At L1 we packed the defect that had been created.

An additional graft was obtained (20937, autograft for spine surgery only [includes harvesting the graft]; morselized [through separate skin or fascial incision]). We ran out of bone and because of this, the eleventh rib was harvested using a separate parietal pleural incision. The packing was continued until the process was completed at all levels. X-rays were taken to verify correct placement, the wound was closed and the patient taken to the recovery room.

Analysis: Reviewing all of the codes submitted, these problems were encountered in the original billing:

63077 (diskectomy, anterior, with decompression of spinal cord and/or nerve root[s], including osteophytectomy; thoracic) was billed but was not supported by any documentation. The osteotomy codes (22222 and 22226) already include the minimal diskectomy reported in the operative note.

Two graft codes, 20936 and 20937, were reported; however, according to CPT rules, only one grafting procedure should be reported per session.

Each additional level was entered separately on the claim form, and this caused denials for duplicate services. When entering additional levels, indicate the quantity in the units field on the HCFA 1500.

The correct coding for this procedure would be:
22810 (the arthrodesis is the most highly valued procedure according to RBRVS); 22222-51 (the -51 modifier is used to signify that this is one of multiple procedures);
22226 x 4 (no modifier is required as these codes are add-on codes and any multiple procedure reduction has already been figured into the relative value for this procedure);
22846 (exempt from modifier -51 per CPT); 20937.

The coder also must be careful to count vertebral segments and interspaces carefully. For instance, in the example, T11-L3, there were five vertebral segments and four interspaces (T11- T12, T12-L1, L1-L2, and L2-L3). Each type of code defines whether segments or spaces should be counted. Osteotomies count segments, since the treatment is to the bone itself. Arthrodesis may be counted by segment or interspace depending on the technique used. Instrumentation counts segments. Because of these variations, you may have a different number treated for each type of procedure performed during the session. You should not assume that the number of segments listed in the heading of the operative report will represent the number for all procedures. Often procedures such as osteotomies may be performed on just several segments, with arthrodesis on more segments.