22633

Arthrodesis, combined posterior or posterolateral technique with posterior interbody technique including laminectomy and/or discectomy sufficient to prepare interspace (other than for decompression), single interspace and segment; lumbar

CPT code 22633 represents a complex, single-level lumbar spinal fusion procedure that combines two distinct arthrodesis techniques: a posterior or posterolateral fusion and a posterior interbody fusion. This combined approach is frequently referred to as a 360-degree fusion performed through a single posterior incision. During the procedure, the surgeon addresses the instability and mechanical pain of the lumbar spine by fusing both the anterior column (the intervertebral disc space) and the posterior column (the facet joints and transverse processes). The procedure specifically includes the laminectomy and/or discectomy required to access and prepare the intervertebral space for the interbody graft, commonly known as a Posterior Lumbar Interbody Fusion (PLIF) or Transforaminal Lumbar Interbody Fusion (TLIF). The provider begins by making a midline posterior incision over the target lumbar level. The paraspinal muscles are retracted to expose the posterior elements. A laminectomy, partial or complete, along with a partial facetectomy, is performed to expose the nerve roots and the intervertebral disc. The disc material is meticulously removed (discectomy), and the cartilaginous endplates of the adjacent vertebral bodies are scraped and prepared to bleeding bone to promote fusion. An interbody spacer or cage, packed with bone graft, is then inserted into the empty disc space, achieving the interbody arthrodesis component. Following this, the surgeon decorticates the posterior bony elements, such as the transverse processes and remaining facet joints. Additional bone graft material is laid over these decorticated posterior elements to facilitate the posterolateral arthrodesis. It is important to note that while this code encompasses the combined fusion techniques and the laminectomy/discectomy necessary for interspace preparation, it does not include the placement of spinal instrumentation (such as pedicle screws and rods) or the harvesting of bone graft from a separate site. These components must be reported with their respective distinct CPT codes. Code 22633 provides robust stabilization for patients suffering from severe degenerative disc disease, unstable spondylolisthesis, recurrent disc herniation, or pseudarthrosis, ensuring immobilization and proper alignment of the affected lumbar segment.

Clinical Indications

  • Degenerative disc disease (DDD) of the lumbar spine
  • Lumbar spondylolisthesis (isthmic or degenerative) with segmental instability
  • Pseudarthrosis or failed previous spinal fusion
  • Recurrent lumbar disc herniation with associated mechanical back pain
  • Lumbar spinal stenosis complicated by iatrogenic or degenerative instability
  • Spinal trauma resulting in fracture or dislocation requiring stabilization
  • Spinal deformity requiring rigid 360-degree stabilization via posterior approach

Procedure Steps

  1. The patient is placed in the prone position under general anesthesia.
  2. A posterior midline incision is made over the specified lumbar segment.
  3. Paraspinal muscles are dissected and retracted laterally to expose the spinous processes, lamina, facet joints, and transverse processes.
  4. A laminectomy and partial facetectomy are performed to decompress the neural elements and provide a safe corridor to the intervertebral disc space.
  5. The thecal sac and nerve roots are carefully retracted.
  6. A thorough discectomy is performed, removing the nucleus pulposus and preparing the cartilaginous endplates to bleeding subchondral bone.
  7. An interbody spacer or cage, filled with autograft or allograft, is inserted into the prepared disc space (PLIF or TLIF approach).
  8. The posterior bony elements (transverse processes, pars, and remaining facet joints) are decorticated using a high-speed burr.
  9. Bone graft material is laid across the decorticated posterolateral gutters.
  10. If planned, pedicle screws and rods are placed (reported separately).
  11. The wound is irrigated, hemostasis is obtained, and the incision is closed in multiple layers.

Coding Guidelines

  • Code 22633 describes a single interspace and segment. For each additional interspace, use add-on code 22634.
  • Do not report 22633 in conjunction with 22612 (posterior/posterolateral fusion) or 22630 (posterior interbody fusion) at the same level.
  • The laminectomy and discectomy performed to prepare the interspace are included. Do not report 63052 or 63053 for decompression at the same interspace.
  • Bone grafting procedures (e.g., 20930, 20931, 20936, 20937, 20938) are reported separately.
  • Spinal instrumentation (e.g., pedicle screws, rods - 22840-22848) is reported separately.
  • If operating on a different anatomical region or distinct separate level not contiguous, modifier 59 or X-modifiers may apply to other codes, but read NCCI edits carefully.
  • Use modifier 62 if two surgeons are acting as co-surgeons (e.g., an orthopedic surgeon and a neurosurgeon).

Associated ICD-10 Codes