UnitedHealthcare Knee Surgery Coverage Update

Coverage criteria for knee cartilage procedures

InterQual-referenced procedures

Covered when InterQual criteria are met for listed procedures

InterQual-based coverage: Coverage for arthroscopy, arthrotomy, total joint replacement, unicondylar/patellofemoral replacement and related knee procedures is determined by meeting the stated InterQual CP clinical criteria listed in the policy.

Refer to InterQual modules named in policy

Unproven / Not Medically Necessary (articular cartilage repair)

The following procedures/technologies are considered unproven and not medically necessary

Not medically necessary technologies: 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); Xenograft implantation.

Listed as unproven due to insufficient evidence of efficacy

Articular cartilage repair using the technologies listed below is considered not medically necessary because current evidence is insufficient to demonstrate efficacy. These technologies are not covered when proposed as treatments for articular cartilage defects.

Available clinical evidence for several emerging cartilage repair technologies is limited by small case series, short-term follow-up, and inconsistent outcomes. For decellularized osteochondral allograft plugs, reports have described implant delamination and high failure rates, including series reporting revision and implant removal; larger, longer randomized trials comparing these plugs to established treatments are needed. Studies of synthetic resorbable polymers (for example, TruFit) are primarily animal studies or small human series and have reported persistent pain, poor graft incorporation, and deterioration of early improvements in some longer-term follow-ups. Evidence for reduced osteochondral allograft discs consists only of small case series and is insufficient to draw conclusions about clinical benefit. Xenograft approaches and other novel biologic or particulate cartilage techniques similarly lack adequate high-quality human data to support routine use.

Technologies and specific products addressed in this policy include: autologous minced or particulated cartilage (e.g., Cartilage Autograft Implantation System [CAIS], Reveille Cartilage Processor); 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 plug, TruGraft granules); and xenograft implantation

Case series and registry reviews of decellularized osteochondral allograft plugs have reported concerning outcomes, including implant delamination and high revision rates. For example, one case series (mean follow-up 15.5 months) reported a 29% revision rate with implant removal, and another series reported implant failure rates as high as 72% within 2 years, indicating insufficient evidence to support routine use.

Evidence for reduced osteochondral allograft discs is limited to small case series. Systematic evidence reviews and single-surgeon case series (e.g., an 18-patient report with two failures) highlight small sample sizes, short follow-up, and potential bias, such that current data are inadequate to establish clinical effectiveness.

Concerns about both decellularized osteochondral plugs and synthetic resorbable polymer implants include high reported failure rates, delamination or poor incorporation of the implant, and persistent symptoms in available studies. Given these safety and effectiveness concerns and the limited quality and size of human studies, routine clinical use of these technologies is not supported by the current evidence.

Procedure and supply codes

Applicable procedure and supply 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.

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Coding details

Coding thresholdsNone listed in policy

Representative CPT/HCPCS examplesIncludes codes such as 29885, 29886, 29887, 29888, 29889, G0428, J7330, S2112

Number of codes referencedMultiple procedure and supply codes listed (see Applicable Codes section)

Provider requirements, prior authorization, and documentation

Prior Authorization
InterQual-based medical necessity and prior authorization
UnitedHealthcare uses InterQualfor primary medical necessity determinations. Procedures that do not meet the applicable InterQual criteria may be denied and may require prior authorization before services are rendered.
InterQual modules referenced: Arthroscopy or Arthroscopically Assisted Surgery, Knee; Arthroscopy, Diagnostic, +/- Synovial Biopsy, Knee; Arthrotomy, Knee; Total Joint Replacement (TJR), Knee; Unicondylar or Patellofemoral Knee Replacement; and pediatric variants
Prior authorization may be required when InterQual criteria apply

Denial Risk
Coverage contingent on InterQual criteria
Coverage for procedures is contingent on meeting InterQual criteria. If the requested service does not meet InterQual-defined medical necessity, the service may be denied in whole or in part.

Clinical background

Articular cartilage has limited intrinsic capacity for healing; focal cartilage defects can cause pain, swelling, and functional limitation. Multiple novel repair approaches (including minced cartilage techniques, decellularized or reduced allografts, synthetic resorbable scaffolds, collagen implants, and xenografts) have been developed to address these defects, but many lack robust clinical data. Because evidence is limited by small studies, short follow-up, and reports of implant-related failures or poor incorporation, these emerging technologies require larger, well-controlled trials before they can be recommended as standard treatment options.

Definitions of devices and techniques

BioCartilage

TermBioCartilage

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

Intended useScaffold for microfracture procedures to treat cartilage defects

Cartilage Autograft Implantation System (CAIS)

TermCartilage Autograft Implantation System (CAIS)

DefinitionSystem that harvests minced autograft cartilage and disperses chondrocytes on a scaffold in a single-stage treatment (Farr et al, 2012)

Policy revision history and material changes

2025-06-01definition update & supporting infoLatest

Updated definition of 'Reduced Allograft Discs' (examples: Cartiform, ProChondrix CR) and updated Supporting Information sections (Clinical Evidence and References).

2025-06-01operational note added

Added operational language clarifying that benefit coverage is determined by federal, state, or contractual requirements and that medical records documentation may be required to assess clinical criteria for coverage (refer to the guideline 'Medical Records Documentation Used for Reviews').

OpenPayer

Surgery of the Knee (Kentucky)