CurrentUnitedHealthcarePolicy CS068ID.C

Surgery of the Knee (for Idaho Only)

Defines UnitedHealthcare medical policy for knee surgery and related articular cartilage repair procedures for Idaho members, including Idaho Medicaid Plus plans; details medical necessity references, unproven procedures, documentation requirements, definitions, and applicable codes.

Policy Summary

PayerUnitedHealthcare

PolicySurgery of the Knee (for Idaho Only)

Policy CodePolicy CS068ID.C

Change TypeNo material change

Effective DateJun 1, 2026

Next Review Date

Key ActionObtain prior authorization when required and submit complete medical records including detailed imaging, prior therapies with dates/duration/reason for discontinuation, and device/product regulatory information as applicable.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

IdahoGeographic scope

InterQual referencedClinical criteria source

Multiple listedUnproven techniques

ExtensiveDocumentation required

RCTs neededEvidence recommendation

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Coverage Criteria

InterQual-based Coverage

Surgery of the knee is medically necessary when the referenced InterQual procedural criteria are met.

InterQual-based medical necessity: Refer to InterQual CP: Arthroscopy or Arthroscopically Assisted Surgery, Knee; Arthroscopy or Arthroscopically Assisted Surgery, Knee (Pediatric); Arthroscopy, Diagnostic, +/- Synovial Biopsy, Knee; Arthrotomy, Knee; Arthrotomy, Knee (Pediatric); Removal and Replacement, Total Joint Replacement (TJR), Knee; Total Joint Replacement (TJR), Knee; Unicondylar or Patellofemoral Knee Replacement.

Coverage requires meeting the InterQual criteria referenced.

Articular Cartilage Repair — Not Medically Necessary / Unproven

Articular cartilage repair procedures considered not medically necessary due to insufficient evidence:

Not medically necessary procedures: Autologous minced or particulated cartilage (e.g., Cartilage Autograft Implantation System [CAIS], Reveille); Allogeneic minced or particulated cartilage (e.g., BioCartilage®, DeNovo NT/ET); Collagen Meniscus Implant (CMI); Decellularized osteochondral allografts (e.g., Chondrofix); Reduced osteochondral discs (e.g., ProChondrix, Cartiform); Synthetic resorbable polymers (e.g., PolyGraft BGS, TruFit, TruGraft); Xenograft implantation.

These procedures are listed as unproven and not medically necessary due to insufficient, low-quality, or inconclusive clinical evidence (case series, limited trial data) and reported device/technique concerns (e.g., delamination, high failure rates).

Overall insufficient evidence — coverage contingent on evidence

Summary of coverage stance and evidence requirements

General coverage stance: Most reviewed technologies for articular cartilage repair (autologous/allogeneic minced or particulated cartilage, BioCartilage, DeNovo NT, collagen meniscus implants, decellularized osteochondral allografts, reduced osteochondral allograft discs, synthetic resorbable polymers, and xenografts) have insufficient, low-quality, or conflicting evidence to establish safety and efficacy for routine use.

Policy requires larger, higher-quality randomized controlled trials with adequate sample size and longer-term follow-up comparing these technologies to established treatments before coverage for routine clinical use can be supported.

Codes in the applicable code lists that are labeled with an asterisk (*) are not on the State of Idaho Medicaid Fee Schedule and therefore may not be covered by the State of Idaho Medicaid Program. Refer to the Idaho Medicaid Provider Handbook for details on non‑covered and excluded services and to verify state-specific authorization or reimbursement rules.

Several minced or particulated cartilage techniques and related products are described in the policy as either not approved in the United States or in early stages of development and testing; examples include particulated juvenile articular cartilage and other autologous or allogeneic minced cartilage approaches. The policy also identifies extracellular matrix products (e.g., BioCartilage) and other emerging technologies for which randomized controlled trial evidence is lacking, and therefore these technologies are considered investigational or unproven.

The policy specifically lists the following articular cartilage repair procedures as unproven and not medically necessary: autologous minced or particulated cartilage (e.g., Cartilage Autograft Implantation System/CAIS, Reveille), allogeneic minced or particulated cartilage (e.g., BioCartilage®, DeNovo NT/ET), collagen meniscus implant, decellularized osteochondral allografts (e.g., Chondrofix), reduced osteochondral discs (e.g., ProChondrix, Cartiform), synthetic resorbable polymers (e.g., PolyGraft BGS, TruFit, TruGraft), and xenograft implantation.

The evidence base for many of the reviewed cartilage repair technologies is limited and of low quality. Supporting data are frequently limited to small case series, in vitro or animal studies, product briefs, or observational reports with high risk of bias (for example, lack of control groups and concurrent procedures). Reported clinical problems include subchondral edema, graft hypertrophy, delamination, high early failure rates for some allograft products, and inconsistent longer‑term outcomes; larger, higher‑quality randomized controlled trials with longer follow‑up are required to establish safety and efficacy.

Coding and Procedures

Applicable CPT/HCPCS Codesmixed

*0737T	Xenograft implantation into the articular surface.
27412	Autologous chondrocyte implantation, knee.
27415	Osteochondral allograft, knee, open.
27416	Osteochondral autograft(s), knee, open (e.g., mosaicplasty) (includes harvesting of autograft[s]).
27418	Anterior tibial tubercleplasty (e.g., Maquet type procedure).
27437	Arthroplasty, patella; without prosthesis.
27438	Arthroplasty, patella; with prosthesis.
27440	Arthroplasty, knee, tibial plateau.
27441	Arthroplasty, knee, tibial plateau; with debridement and partial synovectomy.
27442	Arthroplasty, femoral condyles or tibial plateau(s), knee.

1–10 of 43

1/5

Policy history code notationsCPT | HCPCS | mixed

0737T	Not on Idaho Medicaid Fee Schedule (notation in policy history)
G0428	Not on Idaho Medicaid Fee Schedule (notation in policy history)
J7330	Not on Idaho Medicaid Fee Schedule (notation in policy history)
S2122	Not on Idaho Medicaid Fee Schedule (notation in policy history)
27445	Removed from applicable codes (notation in policy history)

Radiographic criteria for severe osteoarthritis — accepted findings

Accepted radiographic criteriaThree or more moderate to severe radiographic findings (narrowing of joint space, osteophyte formation, subchondral sclerosis, subchondral cysts, deformity of bony end-plates, thinning or loss of articular cartilage) are accepted to support a diagnosis of severe osteoarthritis.

Examples of moderate–severe findingsOsteophyte formation; subchondral sclerosis; subchondral cysts; deformity of bony end-plates; joint-space narrowing; thinning or complete loss of articular cartilage.

Source basisRadiographic Findings of Osteoarthritis defined per ACR (2025) and policy note accepting three or more findings as sufficient to support severe OA.

Provider Actions and Documentation

Prior Authorization

Prior Authorization and Codes (reference)

Prior authorization may be required. Documentation submitted will be used to evaluate clinical criteria and medical necessity.

Applicable procedure/diagnosis codes are listed in the Applicable Codes section; inclusion does not imply coverage or reimbursement.
CPT/HCPCS codes 0737T, G0428, J7330, and S2122 are not on the State of Idaho Medicaid Fee Schedule and therefore may not be covered by the State of Idaho Medicaid Program; verify state-specific coverage and billing rules in the Idaho Medicaid Provider Handbook.

Documentation Required

Prior Therapies Documentation

Provide complete medical records documenting prior therapies tried, failed, or contraindicated. Include dates, duration, and reason for discontinuation for each therapy.

Document nonoperative management (e.g., physical therapy, activity modification, medications) with start and end dates and outcome.

Background

Articular cartilage provides a smooth, low‑friction surface for joint motion and helps distribute load across the joint. Because articular cartilage is avascular and has a limited intrinsic capacity for repair, focal full‑thickness defects often fail to heal and can lead to persistent pain, swelling, and functional disability. A range of biologic and implantable techniques (autograft/allograft cartilage particulation, matrix scaffolds, decellularized allografts, synthetic resorbable polymers, and xenografts) are under investigation to restore cartilage surface and function, but current evidence for many of these approaches is insufficient to support routine coverage.

Definitions

BioCartilage — definition

DefinitionBioCartilage: Dehydrated, micronized allograft articular cartilage matrix intended to provide a scaffold for microfracture; small particles are mixed with a blood solution to create a paste-like consistency applied over a cartilage defect (Hayes, 2022).

Intended useApplied over microfracture-treated defects as a scaffold to support repair tissue formation.

CompositionMicronized allograft articular cartilage matrix (dehydrated particles) mixed intraoperatively with blood solution to form paste.

Cartilage Autograft Implantation System (CAIS) — definition

DefinitionCartilage Autograft Implantation System (CAIS): System that harvests minced autograft cartilage and disperses chondrocytes on a scaffold in a single-stage treatment (Farr et al., 2012).

Procedure type

Revision History

06/01/2026policy_effective / revisionsLatest

Definitions were added (Disabling Pain; Functional Disability; Outerbridge Grades; Radiographic Findings of Osteoarthritis; WOMAC); CPT code 27445 was removed; notation added that CPT/HCPCS codes 0737T, G0428, J7330, and S2122 are not on the State of Idaho Medicaid Fee Schedule; clinical evidence and references sections were updated.

Policy Summary

PayerUnitedHealthcare

PolicySurgery of the Knee (for Idaho Only)

Policy CodePolicy CS068ID.C

Change TypeNo material change

Effective DateJun 1, 2026

Next Review Date

SourceLink

On This Page

Document prior injections or biologic therapies, prior surgeries to the same joint (include date of failed previous surgery), and reasons for revision.

For revision surgery requests, include details of complication(s) and a complete staged surgical plan.

Documentation Required

Medical Records and Imaging Requirements

Submit complete diagnostic imaging reports and interpretation details. When requested, provide the actual diagnostic image(s) labeled with the date taken and the applicable case number or member identifiers; images must be submitted via the external portal as directed.

Imaging report must include size and location of focal full-thickness cartilage defect, Outerbridge grade, joint space and alignment, and ligament tear location/grade.
Include specialty(ies) of the interpreting provider(s) and the impression.
Reports of recent diagnostic tests (microbiology, synovial exam, ESR, CRP) and pertinent physical exam findings should be submitted.

Documentation Required

Device/Tissue Regulatory and Provenance Documentation

Document provenance and regulatory status of any device, biologic, or donor tissue product to be used. Provide the product name, manufacturer, FDA status (if applicable), and evidence of tissue establishment registration for donor-derived products.

For donor tissue products (e.g., DeNovo NT), include FDA Establishment Registration & Device Listing information and donor screening/testing documentation as applicable under HCT/P regulations.
For implants or scaffold products, provide FDA PMN/PMA references or note if a product is not FDA-cleared/approved.

Denial Risk

Unproven / Not Medically Necessary Procedures

The following procedures/products are considered unproven or not medically necessary due to insufficient evidence and are subject to denial.

Autologous minced or particulated cartilage (e.g., Cartilage Autograft Implantation System, Reveille Cartilage Processor)
Allogeneic minced or particulated cartilage (e.g., BioCartilage, DeNovo NT, DeNovo ET)
Collagen Meniscus Implant (CMI) / meniscal scaffolds
Decellularized osteochondral allografts (e.g., Chondrofix)
Reduced osteochondral discs (e.g., Prochondrix, Cartiform)
Synthetic resorbable polymers (e.g., PolyGraft BGS, TruFit, TruGraft)
Xenograft implantation

Denial Risk

High Failure Rates / Insufficient Evidence

Evidence reports of high short-term failure or implant delamination exist for certain technologies; these findings increase likelihood of denial or request for additional justification.

Decellularized osteochondral allograft plugs have been associated with implant delamination and high failure rates (e.g., series reporting 29% revision at mean 15.5 months; other series reporting up to 72% failure within 2 years).
Extracellular matrix products such as BioCartilage lack sufficient randomized trial evidence to support improved clinical outcomes compared with established treatments.

Step Therapy

No Step Therapy Specified

No formal step therapy program is specified for these technologies in this policy; however, standard conservative therapy documentation is expected as part of the prior therapies requirement.

There is no explicit step therapy sequence required by this policy for cartilage repair technologies.
Clinical reviewers will evaluate whether appropriate conservative measures were attempted before advanced or investigational procedures.

Single-stage autologous minced cartilage harvest and implantation onto scaffold during the same operation.

Example devices/techniqueDevices/processors that mince autologous cartilage for immediate reimplantation (e.g., Reveille Cartilage Processor referenced elsewhere).

Collagen Meniscus Implant — definition

DefinitionCollagen Meniscus Implants: Implantable porous meniscus scaffolds composed of collagen fibers, enriched with glycosaminoglycan, used as a template and support for generation of new tissue to replace lost menisci (AAOS, 2023).

Intended purposeProvide a scaffold to support meniscal tissue regeneration and fill meniscal defects.

Alternate namesAlso described as collagen scaffolds (e.g., CMI, Menaflex in coding descriptions).

Reduced Allograft Discs — definition

DefinitionReduced Allograft Discs: Wafer-thin allografts in which the bony portion is reduced; discs contain hyaline cartilage with chondrocytes, growth factors, and extracellular matrix proteins and are often used with marrow stimulation to promote host cell infiltration and chondrogenesis (Hayes, 2018; updated 2021).

Clinical applicationUsed to fill chondral defects often in conjunction with marrow stimulation to facilitate integration and matrix production.

ExamplesCommercial examples include Cartiform and ProChondrix CR as cited in the policy text.

Synthetic Resorbable Polymers — definition

DefinitionSynthetic Resorbable Polymers: Implants that function as a scaffold for chondral and osteogenic cells with the synthetic polymer being resorbed as the cells produce their normal matrices (AAOS, 2023).

MechanismProvide temporary scaffold for cell infiltration and matrix formation; polymer gradually resorbs while native matrix replaces it.

Evidence notePolicy notes evidence mainly from animal studies with limited human data; considered unproven in many applications.

WOMAC — definition and purpose

DefinitionWOMAC (Western Ontario and McMaster Universities Arthritis Index): Disease-specific, self-administered questionnaire for hip/knee osteoarthritis composed of 24 items grouped into pain, stiffness, and physical function domains.

DomainsPain, stiffness, and physical function (multi-dimensional scale of 24 items).

Use in policyWOMAC thresholds are used in definitions for Disabling Pain and Functional Disability (e.g., domain scores > 40).

Outerbridge Grades — definition

Grade I–IV definitionsOuterbridge Grades describe articular cartilage condition: Grade 0 normal; Grade I softening/swelling; Grade II partial-thickness defect with fissures not to subchondral bone or ≤1.5 cm; Grade III fissuring to subchondral bone >1.5 cm; Grade IV exposed subchondral bone.

Clinical useUsed to characterize cartilage lesion severity during arthroscopy or imaging reports for policy determinations.

ReferenceOuterbridge grading scale cited (Slattery, 2018) in policy definitions section.

Policy-specific clinical definitions

Disabling Pain (policy-specific)Defined as WOMAC pain domain score > 40 (Quintana, 2009).

Functional Disability (policy-specific)Defined as WOMAC functional limitation domain score > 40 (Quintana, 2009).

Radiographic Findings of Osteoarthritis (policy-specific)Includes narrowing of joint space, osteophyte formation, subchondral sclerosis, subchondral cysts, deformity of bony end-plates, and thinning or complete loss of articular cartilage; policy accepts three or more moderate to severe findings to support severe OA.

WOMAC (policy-specific)WOMAC is the specified instrument for assessing pain, stiffness, and physical function; used to determine disabling pain and functional disability thresholds.