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Official Description

Arthrodesis, posterior technique, atlas-axis (C1-C2)

© Copyright 2025 American Medical Association. All rights reserved.

Common Language Description

The procedure described by CPT® Code 22595 refers to arthrodesis using a posterior technique specifically for the atlas-axis, which is the anatomical region encompassing the first two cervical vertebrae, known as C1 (atlas) and C2 (axis). This area is critical for the rotational movement of the head, allowing for side-to-side motion. The C1-C2 articulation consists of three distinct joints: the central atlantoaxial joint and two lateral atlantoaxial joints. The primary goal of performing a posterior arthrodesis at this site is to reduce the range of motion in the neck, particularly the rotation, and to prevent any forward or backward movement of the head, which can be essential in cases of instability or injury. During the procedure, an incision is made at the back of the neck to access the C1-C2 joint, allowing for the dissection of soft tissues to expose the vertebrae. If there are any fractures or instability present, additional treatments may be performed concurrently. A bone graft, which is often harvested from the iliac crest or another site, is prepared and placed between the vertebrae to promote fusion. To ensure immobilization of the joint, drill holes are created in the C1 and C2 vertebrae, and wires or other internal fixation devices may be utilized. The procedure may also involve the placement of a drain to manage any postoperative fluid accumulation, and the surgical site is closed in layers to promote healing.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

The indications for performing a posterior arthrodesis of the atlas-axis (C1-C2) include the following:

  • Fractures of C1-C2 These fractures may result from trauma and can lead to instability in the cervical spine, necessitating surgical intervention to restore stability.
  • Instability of C1-C2 Conditions that cause instability in this region, such as congenital anomalies or degenerative diseases, may require fusion to prevent further neurological compromise or pain.
  • Severe neck pain Associated with instability or degenerative changes in the C1-C2 region may warrant surgical fusion to alleviate symptoms and improve quality of life.

2. Procedure

The procedure for posterior arthrodesis of the atlas-axis involves several critical steps, which are detailed as follows:

  • Step 1: Incision and Exposure An incision is made in the posterior aspect of the neck over the C1-C2 joint. This incision allows the surgeon to access the underlying structures. Soft tissues, including muscles and ligaments, are carefully dissected to expose the C1 and C2 vertebrae, ensuring minimal damage to surrounding tissues.
  • Step 2: Fracture Treatment or Decompression If there are any fractures present or if decompression of neural structures is necessary, these procedures are performed at this stage. This step is crucial for addressing any immediate concerns related to spinal stability or nerve compression.
  • Step 3: Bone Graft Preparation A bone graft is obtained, typically from the iliac crest or another suitable donor site. This graft is prepared for placement between the C1 and C2 vertebrae, which is essential for promoting fusion and stability in the joint.
  • Step 4: Placement of Bone Graft The prepared bone graft is then placed between the C1 and C2 vertebrae. This graft serves as a scaffold for new bone growth, facilitating the fusion process.
  • Step 5: Immobilization To ensure the immobilization of the joint, drill holes are created in both the C1 and C2 vertebrae. Wires are threaded through these holes to secure the vertebrae together, or alternatively, other reportable internal fixation devices may be utilized to achieve the same goal.
  • Step 6: Drain Placement and Closure A drain may be placed to prevent fluid accumulation at the surgical site. Finally, the surgical wound is closed in layers, ensuring proper healing and minimizing the risk of infection.

3. Post-Procedure

Post-procedure care for patients undergoing posterior arthrodesis of the atlas-axis typically involves monitoring for any complications, managing pain, and ensuring proper healing of the surgical site. Patients may be advised to limit neck movement to promote fusion and may require a cervical collar for support during the initial recovery phase. Follow-up appointments are essential to assess the healing process and to determine when normal activities can be resumed. Rehabilitation may also be recommended to restore strength and mobility in the neck following the procedure.

Short Descr ARTHRD PST TQ ATLAS-AXIS
Medium Descr ARTHRODESIS POSTERIOR ATLAS-AXIS C1-C2
Long Descr Arthrodesis, posterior technique, atlas-axis (C1-C2)
Status Code Active Code
Global Days 090 - Major Surgery
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 2 - Payment restriction for assistants at surgery does not apply to this procedure...
Co-Surgeons (62) 2 - Co-surgeons permitted and no documentation required if the two- specialty requirement is met.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Inpatient Procedures, not paid under OPPS
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P3D - Major procedure, orthopedic - other
MUE 1
CCS Clinical Classification 158 - Spinal fusion

This is a primary code that can be used with these additional add-on codes.

20705 Add-on Code MPFS Status: Active Code APC N Removal of drug-delivery device(s), intra-articular (List separately in addition to code for primary procedure)
20930 Addon Code MPFS Status: Bundled Code APC N ASC N1 CPT Assistant Article Allograft, morselized, or placement of osteopromotive material, for spine surgery only (List separately in addition to code for primary procedure)
20931 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Allograft, structural, for spine surgery only (List separately in addition to code for primary procedure)
20936 Addon Code MPFS Status: Bundled Code APC N ASC N1 CPT Assistant Article Autograft for spine surgery only (includes harvesting the graft); local (eg, ribs, spinous process, or laminar fragments) obtained from same incision (List separately in addition to code for primary procedure)
20937 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Autograft for spine surgery only (includes harvesting the graft); morselized (through separate skin or fascial incision) (List separately in addition to code for primary procedure)
20938 Addon Code MPFS Status: Active Code APC N ASC N1 CPT Assistant Article Autograft for spine surgery only (includes harvesting the graft); structural, bicortical or tricortical (through separate skin or fascial incision) (List separately in addition to code for primary procedure)
20939 Addon Code MPFS Status: Active Code APC N ASC N1 Bone marrow aspiration for bone grafting, spine surgery only, through separate skin or fascial incision (List separately in addition to code for primary procedure)
22840 Addon Code MPFS Status: Active Code APC N ASC N1 Physician Quality Reporting CPT Assistant Article Posterior non-segmental instrumentation (eg, Harrington rod technique, pedicle fixation across 1 interspace, atlantoaxial transarticular screw fixation, sublaminar wiring at C1, facet screw fixation) (List separately in addition to code for primary procedure)
22841 Addon Code MPFS Status: Bundled Code APC C Physician Quality Reporting CPT Assistant Article Internal spinal fixation by wiring of spinous processes (List separately in addition to code for primary procedure)
22842 Addon Code MPFS Status: Active Code APC N ASC N1 Physician Quality Reporting CPT Assistant Article Posterior segmental instrumentation (eg, pedicle fixation, dual rods with multiple hooks and sublaminar wires); 3 to 6 vertebral segments (List separately in addition to code for primary procedure)
22843 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Posterior segmental instrumentation (eg, pedicle fixation, dual rods with multiple hooks and sublaminar wires); 7 to 12 vertebral segments (List separately in addition to code for primary procedure)
22844 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Posterior segmental instrumentation (eg, pedicle fixation, dual rods with multiple hooks and sublaminar wires); 13 or more vertebral segments (List separately in addition to code for primary procedure)
22845 Addon Code MPFS Status: Active Code APC N ASC N1 Physician Quality Reporting CPT Assistant Article Illustration for Code Anterior instrumentation; 2 to 3 vertebral segments (List separately in addition to code for primary procedure)
22846 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Illustration for Code Anterior instrumentation; 4 to 7 vertebral segments (List separately in addition to code for primary procedure)
22847 Addon Code MPFS Status: Active Code APC C Physician Quality Reporting CPT Assistant Article Illustration for Code Anterior instrumentation; 8 or more vertebral segments (List separately in addition to code for primary procedure)
22848 Addon Code MPFS Status: Active Code APC N Physician Quality Reporting CPT Assistant Article Pelvic fixation (attachment of caudal end of instrumentation to pelvic bony structures) other than sacrum (List separately in addition to code for primary procedure)
22853 CPT Add On MPFS Status: Active Code APC N ASC N1 Insertion of interbody biomechanical device(s) (eg, synthetic cage, mesh) with integral anterior instrumentation for device anchoring (eg, screws, flanges), when performed, to intervertebral disc space in conjunction with interbody arthrodesis, each interspace (List separately in addition to code for primary procedure)
22854 CPT Add On MPFS Status: Active Code APC N ASC N1 Insertion of intervertebral biomechanical device(s) (eg, synthetic cage, mesh) with integral anterior instrumentation for device anchoring (eg, screws, flanges), when performed, to vertebral corpectomy(ies) (vertebral body resection, partial or complete) defect, in conjunction with interbody arthrodesis, each contiguous defect (List separately in addition to code for primary procedure)
22859 CPT Add On CPT Resequenced MPFS Status: Active Code APC N ASC N1 Insertion of intervertebral biomechanical device(s) (eg, synthetic cage, mesh, methylmethacrylate) to intervertebral disc space or vertebral body defect without interbody arthrodesis, each contiguous defect (List separately in addition to code for primary procedure)
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
GC This service has been performed in part by a resident under the direction of a teaching physician
82 Assistant surgeon (when qualified resident surgeon not available): the unavailability of a qualified resident surgeon is a prerequisite for use of modifier 82 appended to the usual procedure code number(s).
62 Two surgeons: when 2 surgeons work together as primary surgeons performing distinct part(s) of a procedure, each surgeon should report his/her distinct operative work by adding modifier 62 to the procedure code and any associated add-on code(s) for that procedure as long as both surgeons continue to work together as primary surgeons. each surgeon should report the co-surgery once using the same procedure code. if additional procedure(s) (including add-on procedure(s) are performed during the same surgical session, separate code(s) may also be reported with modifier 62 added. note: if a co-surgeon acts as an assistant in the performance of additional procedure(s), other than those reported with the modifier 62, during the same surgical session, those services may be reported using separate procedure code(s) with modifier 80 or modifier 82 added, as appropriate.
22 Increased procedural services: when the work required to provide a service is substantially greater than typically required, it may be identified by adding modifier 22 to the usual procedure code. documentation must support the substantial additional work and the reason for the additional work (ie, increased intensity, time, technical difficulty of procedure, severity of patient's condition, physical and mental effort required). note: this modifier should not be appended to an e/m service.
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
53 Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
78 Unplanned return to the operating/procedure room by the same physician or other qualified health care professional following initial procedure for a related procedure during the postoperative period: it may be necessary to indicate that another procedure was performed during the postoperative period of the initial procedure (unplanned procedure following initial procedure). when this procedure is related to the first, and requires the use of an operating/procedure room, it may be reported by adding modifier 78 to the related procedure. (for repeat procedures, see modifier 76.)
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
80 Assistant surgeon: surgical assistant services may be identified by adding modifier 80 to the usual procedure number(s).
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
CR Catastrophe/disaster related
ET Emergency services
GW Service not related to the hospice patient's terminal condition
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
Date
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2022-01-01 Note Short description changed.
Pre-1990 Added Code added.
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