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Official Description

Arthrodesis; subtalar

© Copyright 2025 American Medical Association. All rights reserved.

Common Language Description

Arthrodesis of the subtalar joint is a surgical procedure aimed at fusing the talus and calcaneus bones in the foot. This procedure is typically indicated for patients suffering from severe arthritis, avascular necrosis of the bones that form the ankle joint, or complications arising from previous surgeries such as failed total ankle arthroplasty. Additionally, it may be performed to correct deformities resulting from trauma, congenital anomalies like untreated clubfoot, or deformities associated with neuromuscular diseases. The subtalar joint plays a crucial role in foot movement and stability, and its fusion can alleviate pain and improve function in patients with significant joint damage. The surgical approach involves making an incision over the talocalcaneal joint, carefully exposing the posterior facet, and excising the articular cartilage and any necessary bone to achieve proper alignment and stabilization of the joint. This procedure is essential for restoring mobility and reducing discomfort in affected individuals.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

The subtalar arthrodesis procedure is indicated for the following conditions:

  • Severe Arthritis - This condition involves inflammation of the subtalar joint, leading to pain and reduced mobility.
  • Avascular Necrosis - This occurs when there is a loss of blood supply to the bones forming the ankle joint, resulting in bone death and joint dysfunction.
  • Failed Total Ankle Arthroplasty - This refers to unsuccessful outcomes from previous ankle replacement surgeries, necessitating further intervention.
  • Deformities Due to Trauma - Injuries that result in structural changes to the foot may require surgical correction through arthrodesis.
  • Congenital Anomalies - Conditions such as severe untreated clubfoot that affect foot structure and function can be addressed with this procedure.
  • Deformities Due to Neuromuscular Disease - Neuromuscular conditions that lead to abnormal foot positioning may necessitate surgical intervention to restore function.

2. Procedure

The subtalar arthrodesis procedure involves several critical steps to ensure successful fusion of the talus and calcaneus bones:

  • Incision - A surgical incision is made over the talocalcaneal joint to provide access to the subtalar area.
  • Exposure of the Posterior Facet - The posterior facet of the subtalar joint is carefully exposed to allow for the necessary surgical interventions.
  • Excising Articular Cartilage - The articular cartilage is excised to prepare the joint surfaces for fusion, ensuring that the underlying bone is adequately prepared.
  • Bone Excision as Needed - Additional bone may be excised to achieve the desired alignment and positioning of the foot.
  • Stabilization - The talus and calcaneus are stabilized using screw fixation to maintain the proper position during the healing process.
  • Bone Graft Placement - A bone graft may be placed in the joint space to promote healing and enhance the fusion process.
  • Closure of Incisions - After the procedure, the incisions are closed, and the foot is placed in a short leg cast or cast boot to immobilize the area and support recovery.

3. Post-Procedure

Following the subtalar arthrodesis, patients can expect a recovery period that may involve immobilization of the foot in a short leg cast or cast boot to ensure proper healing of the fused joint. Pain management and rehabilitation exercises may be initiated as directed by the healthcare provider to promote mobility and strength. Regular follow-up appointments will be necessary to monitor the healing process and assess the success of the fusion. Patients should be advised on activity restrictions during the recovery phase to prevent complications and ensure optimal outcomes.

Short Descr ARTHRODESIS SUBTALAR
Medium Descr ARTHRODESIS SUBTALAR
Long Descr Arthrodesis; subtalar
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 Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Device-intensive procedure added to ASC list in CY 2008 or later; paid at adjusted rate.
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)
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
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).
GC This service has been performed in part by a resident under the direction of a teaching physician
80 Assistant surgeon: surgical assistant services may be identified by adding modifier 80 to the usual procedure number(s).
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.
50 Bilateral procedure: unless otherwise identified in the listings, bilateral procedures that are performed at the same session, should be identified by adding modifier 50 to the appropriate 5 digit code. 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).
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.
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.
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
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.)
81 Minimum assistant surgeon: minimum surgical assistant services are identified by adding modifier 81 to the usual procedure number.
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).
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
F1 Left hand, second digit
GW Service not related to the hospice patient's terminal condition
SG Ambulatory surgical center (asc) facility service
T5 Right foot, great toe
T6 Right foot, second digit
UD Medicaid level of care 13, as defined by each state
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
Date
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2025-01-01 Changed Short Description changed.
Pre-1990 Added Code added.
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