CurrentCignaPolicy 0486

Subtalar Joint Implantation (Arthroereisis)

Defines Cigna's coverage stance on subtalar joint implantation (subtalar arthroereisis/extraosseous talotarsal stabilization) for treatment of pes planus and related indications for members covered by Cigna plans.

Policy Summary

PayerCigna

PolicySubtalar Joint Implantation (Arthroereisis) — Clinical/Medical Policy

Policy CodePolicy 0486

Change TypeAnnual review — no material changes

Effective DateOct 15, 2024

Next Review DateOct 15, 2025

Key ActionDo not expect prior authorization to result in coverage; report procedures with codes 28899, 0335T, or S2117 only with understanding they are considered experimental/investigational and likely to be denied.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

experimentalcoverage stance

46%implant removal (adult PTTD)

22.1%implant removal (AAFD/PTTD series)

4.8%-18.6%complication range

No changeannual review

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Coverage Determination

Overall coverage determination

Covered when ALL of the following are met

Policy stance: Subtalar joint implantation (subtalar arthroereisis/extraosseous talotarsal stabilization) is considered experimental, investigational or unproven for ANY indication

Policy states no indications are covered

Subtalar joint implantation (also referred to as subtalar arthroereisis or extraosseous talotarsal stabilization) is considered experimental, investigational or unproven for ANY indication. This includes, but is not limited to, treatment of rigid or flexible pes planus (flatfoot), posterior tibial tendon dysfunction, and talotarsal joint subluxation/dislocation.

The following codes are identified in this policy as being used to report subtalar joint implantation procedures and are classified as experimental/investigational/unproven when used for that purpose: 28899 (Unlisted procedure, foot or toes), 0335T (Insertion of sinus tarsi implant), and S2117 (Arthroereisis, subtalar).

Because subtalar joint implantation is considered experimental, investigational, or unproven, the procedure is not medically necessary for any indication described in this policy and is therefore not supported for coverage.

Procedures billed using codes 28899, 0335T, or S2117 to report subtalar joint implantation are classified by this policy as unproven and are not supported as medically necessary for this use.

Billing and Code Classification

Considered Experimental/Investigational/UnprovenCPT | HCPCS | mixedExperimental

28899	Unlisted procedure, foot or toes.
0335T	Insertion of sinus tarsi implant
S2117	Arthroereisis, subtalar

Provider Responsibilities and Billing Guidance

Prior Authorization

Prior Authorization Expected

Prior authorization: Prior authorization is expected for requests involving subtalar joint implantation (subtalar arthroereisis/extraosseous talotarsal stabilization). Submission of a prior authorization request does not, by itself, establish that the service is covered because subtalar joint implantation is considered experimental, investigational or unproven for ANY indication.

Affected procedures: subtalar arthroereisis/extraosseous talotarsal stabilization

Denial Risk

Prior Authorization Not Sufficient for Coverage

Subtalar joint implantation is considered experimental, investigational or unproven for any indication. Prior authorization alone is not sufficient to qualify an otherwise non-covered or investigational service for reimbursement.

Examples of indications: rigid or flexible pes planus, posterior tibial tendon dysfunction, talotarsal joint subluxation/dislocation

Clinical Background

Pes planus (flatfoot) is characterized by loss of the normal medial longitudinal arch and may be described as flexible or rigid. Most cases are flexible and can be asymptomatic or associated with pain and functional limitation. Treatment typically begins with conservative measures—such as foot orthoses, stretching, shoe modification, nonsteroidal anti-inflammatory drugs, physical therapy, and corticosteroid injections—and may progress to surgical options when conservative care fails. Subtalar arthroereisis refers to insertion of an implant into the sinus tarsi intended to limit subtalar motion, improve weight-bearing position during gait, and reduce calcaneal eversion; devices are variably described as self-locking wedges, axis-altering devices, or impact-blocking devices.

Key Terms

Arthroereisis (subtalar joint implantation / extraosseous talotarsal stabilization) — definition and mechanism

DefinitionA surgical procedure in which an implant is inserted into the sinus tarsi to decrease subtalar range of motion, improve weight-bearing position during gait, and limit calcaneal eversion.

Intended mechanismLimits excessive subtalar motion by placing an extraosseous implant in the sinus tarsi to improve foot alignment and weight‑bearing during the gait cycle.

Device categoriesImplants are categorized by biomechanical properties as self‑locking wedges, axis‑altering devices, or impact‑blocking devices.

Clinical uses proposedProposed for treatment of pes planus (flatfoot), posterior tibial tendon dysfunction, and talotarsal joint dislocation.

Potential complicationsReported complications include persistent sinus tarsi pain, foreign body reaction, implant failure, talar fracture, undercorrection, and osteonecrosis of the talus.

Policy Summary

PayerCigna

PolicySubtalar Joint Implantation (Arthroereisis) — Clinical/Medical Policy

Policy CodePolicy 0486

Change TypeAnnual review — no material changes

Effective DateOct 15, 2024

Next Review DateOct 15, 2025

SourceLink

On This Page

Note

Conservative Therapy Context

Conservative therapy should be attempted and documented prior to consideration of surgical intervention. Conservative treatments include foot orthoses, stretching, shoe modification, nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, and corticosteroid injections. Surgery is typically considered only when conservative management does not adequately alleviate symptoms.

Document attempts and response to conservative measures in the medical record prior to surgery consideration

Documentation Required

Billing and Coding Documentation

Billing and coding: Providers must report the most appropriate and current procedure and diagnosis codes as of the date of service. Claims submitted without covered code(s) under this policy will be denied as not covered. Use of codes that are not covered by this policy may result in claim denial.

Ensure claims include covered diagnosis/procedure codes consistent with the policy and member benefit plan
Claims without covered code(s) will be denied as not covered

Documentation Required

Coding Currency and Documentation

Coding currency and documentation: Confirm that codes billed are effective and not deleted at the time of service. AMA and CMS code updates may occur more frequently than policy updates; providers are responsible for using current coding guidance and documenting support for billed services.

Verify code status on the date of service (active/not deleted)
Maintain documentation supporting medical necessity and code selection

Denial Risk

Experimental/Investigational Coding Denial Risk

Denial risk for experimental/unproven codes: Reporting unlisted or investigational procedure codes for subtalar joint implantation may be denied as not covered. Providers should anticipate denials when using codes associated with subtalar arthroereisis because the procedure is considered experimental/investigational/unproven.

Codes considered experimental/unproven for subtalar implantation: 28899, 0335T, S2117
Use of these codes to report subtalar joint implantation may be denied

Subtalar joint implantation (sinus tarsi implant, arthroereisis) — alternative terminology

Synonyms/Alternative termsSubtalar arthroereisis; extraosseous subtalar joint implantation; subtalar joint implantation; sinus tarsi implant.

Common procedure descriptorsInsertion of sinus tarsi implant; arthroereisis, subtalar.

Associated billing codes (considered experimental/unproven)28899 (Unlisted procedure, foot or toes), 0335T (Insertion of sinus tarsi implant), S2117 (Arthroereisis, subtalar).

Policy shorthandOften referenced as sinus tarsi implant or subtalar arthroereisis in clinical and regulatory materials.