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Official Description

Arthrodesis, knee, any technique

© Copyright 2025 American Medical Association. All rights reserved.

Common Language Description

Arthrodesis of the knee, commonly known as knee fusion, is a surgical procedure aimed at permanently joining the bones of the knee joint. This procedure is primarily indicated for patients who have experienced failure of a total knee replacement, where the artificial joint has not functioned as intended. The goal of knee arthrodesis is to alleviate pain and restore stability to the knee by eliminating the joint space, thereby preventing further movement that could cause discomfort. Various techniques can be employed during the procedure, including internal fixation, external fixation, and the use of bone grafts to facilitate the fusion process. The procedure typically begins with the removal of the failed total knee prosthesis, which is a separately reportable surgical intervention. Following this, the surgeon exposes the vascular bone on both the femur and tibia, preparing them for fusion. The alignment of the joint is carefully considered, with specific angles of valgus and flexion to ensure optimal positioning for healing. Overall, knee arthrodesis is a complex procedure that requires meticulous planning and execution to achieve successful outcomes for patients suffering from severe knee issues.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

Arthrodesis of the knee is performed for specific indications, primarily related to the failure of previous knee surgeries or conditions that compromise the integrity and function of the knee joint. The following are the key indications for this procedure:

  • Failed Total Knee Replacement This is the most common indication for knee arthrodesis, where the previously implanted total knee prosthesis has not provided the expected relief from pain or has resulted in complications.
  • Severe Osteoarthritis In cases where osteoarthritis has led to significant joint degeneration and pain, arthrodesis may be considered as a last resort to provide stability and pain relief.
  • Post-Traumatic Arthritis Following severe injuries to the knee that result in joint instability or chronic pain, arthrodesis may be indicated to stabilize the joint.
  • Infection In cases where there is an infection in the knee joint that cannot be resolved through other means, arthrodesis may be necessary to eliminate the joint space and prevent further complications.

2. Procedure

The procedure for knee arthrodesis involves several critical steps to ensure successful fusion of the knee joint. Each step is designed to prepare the bones for fusion and to stabilize the joint effectively.

  • Step 1: Removal of the Total Knee Prosthesis If the procedure is being performed due to a failed total knee replacement, the first step involves the careful removal of the existing prosthesis. This is a separate reportable procedure that must be documented appropriately.
  • Step 2: Exposure of Vascular Bone Once the prosthesis is removed, the surgeon exposes the vascular bone on both the femur and tibia. This exposure is crucial for the subsequent steps, as it allows for proper alignment and preparation of the bones for fusion.
  • Step 3: Cutting the Tibial Bone The tibial bone is then cut first, with careful attention to the slope of the cuts in both the coronal and sagittal planes. This precision is essential to ensure proper alignment of the joint.
  • Step 4: Joint Alignment The knee joint is aligned in a position of 0-5 degrees of valgus and 10-15 degrees of flexion. This alignment is critical for achieving optimal function and stability post-surgery.
  • Step 5: Cutting the Femur Following the tibial cut, the femur is cut in a line that is parallel to the surface of the tibia. This step is vital for ensuring that the two bones will fuse correctly.
  • Step 6: Evaluation of Shortening The surgeon evaluates the amount of shortening that results from the preparation of the joint. This assessment is important for determining whether additional length is needed for proper alignment.
  • Step 7: Use of Bone Grafts If necessary, bone grafts may be utilized to provide a minimal amount of additional length and to enhance the fusion process. These grafts are placed around the periphery of the knee joint.
  • Step 8: Application of Fixation Device An internal or external compression fixator device is then placed to stabilize the joint. Alternatively, intramedullary nail fixation may be employed, depending on the surgeon's preference and the specific case.
  • Step 9: Tightening the Device If a compression fixator device is used, it is tightened to ensure adequate stabilization of the joint during the healing process.
  • Step 10: Closure of the Incision Finally, the surgical incision is closed in layers, ensuring proper healing and minimizing the risk of infection.

3. Post-Procedure

After the knee arthrodesis procedure, patients can expect a recovery period that may vary based on individual circumstances and the complexity of the surgery. Post-operative care typically includes monitoring for signs of infection, managing pain, and ensuring proper alignment of the joint during the healing process. Patients may be advised to limit weight-bearing activities initially and may require physical therapy to regain strength and mobility in the surrounding muscles. Follow-up appointments are essential to assess the healing process and to make any necessary adjustments to the fixation device. The overall goal of post-procedure care is to facilitate a successful fusion of the knee joint while minimizing complications and promoting optimal recovery.

Short Descr FUSION OF KNEE
Medium Descr ARTHRODESIS KNEE ANY TECHNIQUE
Long Descr Arthrodesis, knee, any technique
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) 1 - 150% payment adjustment for bilateral procedures applies.
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) 1 - Co-surgeons could be paid, though supporting documentation is required...
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 162 - Other OR therapeutic procedures on joints

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)
RT Right side (used to identify procedures performed on the right side of the body)
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).
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).
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
CR Catastrophe/disaster related
GC This service has been performed in part by a resident under the direction of a teaching physician
GZ Item or service expected to be denied as not reasonable and necessary
LT Left side (used to identify procedures performed on the left side of the body)
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