CurrentMass General Brigham Health PlanPolicy 07

Autologous Chondrocyte Implantation (ACI) in the Knee

Defines Mass General Brigham Health Plan's medical necessity criteria, coverage stance, and prior authorization requirements for autologous chondrocyte implantation (including MACI) for knee cartilage defects for applicable members.

Policy Summary

PayerMass General Brigham Health Plan

PolicyAutologous Chondrocyte Implantation (ACI) in the Knee

Policy CodePolicy 07

Change TypeAnnual updatematerial changes

Effective Date

Next Review Date

Key ActionTreating specialist must request prior authorization and submit documentation demonstrating age, BMI, defect size and location, symptom duration, and failed conservative therapy.

SourceLink

POLICY UPDATE CHANGES

Added BMI restriction.

Coverage guidelines now point to a custom subset in InterQual for determinations.

Policy language revised to allow up to age 55.

Policy specifies it allows MACI (matrix-induced ACI) and removed older Carticel product.

Medicare variation language clarified and Medicare guidance referenced where applicable.

15-55covered member age range

<35BMI requirement

>=2.0min defect size (cm2)

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6 monthsmin symptom duration

Coverage Criteria for ACI/MACI (Knee)

Initial Coverage Criteria

Covered when ALL of the following are met:

Primary coverage criteria: Member is 15-55 years of age (adolescents must be skeletally mature with documented growth plate closure)age 15-55

Symptom duration: Symptoms of knee pain interfere with activities of daily living and have persisted for at least six months>=6 months

BMI: Body mass index (BMI) less than 35 kg/m2<35 kg/m2

Defect size: Single or multiple full-thickness cartilage defects each measuring greater than or equal to 2.0 cm2>=2.0 cm2

Full-thickness defined as lesions that extend through to the subchondral bone

Defect cause/location: Femoral condyle defects result from acute or repetitive trauma and involve weight-bearing areas of the femoral condyle (medial, lateral, or trochlear) or the patella as documented (e.g., prior arthroscopy)location: weight-bearing femoral condyle or patella

Prior conservative treatment including physical therapy, nonsteroidal anti-inflammatory medications, and steroid injections have failed to offer relieffailed conservative care

Rehabilitation willingness: Member must be willing to comply with a vigorous rehabilitation program post-procedurewillingness to comply

Knee stability/alignment: Knee instability, cruciate ligament laxity, or abnormal joint alignment should be corrected prior to or concurrent with ACI as these may adversely affect success; anterior and posterior cruciate ligaments should be stable and intactstable/ corrected knee

Mass General Brigham Health Plan excludes autologous chondrocyte implantation (ACI/MACI) when the procedure is proposed for joints other than the knee, when there is an active infection of the knee, or when there is the presence of osteoarthritis.

Treatment with ACI/MACI is not covered for indications involving joints other than the knee, for procedures performed in the setting of an active knee infection, or when the knee demonstrates evidence of osteoarthritis.

Coding, Eligibility Basics, and Key Quantitative Criteria

Informational codes listedmixed

27412	Autologous chondrocyte implantation, knee.
27416	Osteochondral autograft(s), knee, open (e.g., mosaicplasty) (includes harvesting of autograft[s]).
29866	Arthroscopy, knee, surgical; osteochondral autograft(s) (e.g., mosaicplasty) (includes harvesting of the autograft[s]).
J7330	Autologous cultured chondrocytes, implant.

Minimum defect size — per-defect threshold

Minimum defect size (per defect)>= 2.0 cm2

Defect countSingle or multiple full-thickness cartilage defects each meeting the size threshold

Documentation requirementMeasurement(s) must be documented in imaging or operative reports

Age range

Allowed age range15–55 years

Adolescent requirementIf adolescent, must be >=15 years and skeletally mature with documented growth plate closure

Provider Responsibilities, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization Required

Prior authorization is required for all autologous chondrocyte implantation (ACI) and matrix-induced ACI (MACI) requests. The treating specialist must request prior authorization and the request will be evaluated against the plan's medical necessity criteria.

Authorization required for Commercial, Qualified Health Plans, MassHealth, and Medicare Advantage

Documentation Required

Conservative Therapy Requirement

Prior conservative therapy must have failed before ACI/MACI will be considered medically necessary. Documented failure should include trials of physical therapy, nonsteroidal anti-inflammatory medications, and steroid injections without adequate symptom relief.

Document prior physical therapy, NSAID use, and steroid injection attempts and durations

Background and Scope

Autologous chondrocyte implantation (ACI), including matrix‑induced ACI (MACI), is a two‑step, cell‑based procedure in which cartilage tissue is harvested from a non‑weight bearing area, chondrocytes are cultured ex vivo, and the cultured cells are implanted into symptomatic, full‑thickness cartilage defects of the knee. MACI refers specifically to implantation of autologous cultured chondrocytes on a porcine collagen membrane and is used to repair single or multiple symptomatic, full‑thickness defects of the adult knee.

Definitions

Definition — Autologous chondrocyte implantation (procedure summary)

Procedure summaryAutologous chondrocyte implantation (ACI) is a two-step, cell-based procedure: healthy cartilage is harvested from a non–weight-bearing area, chondrocytes are cultured (typically 3–5 weeks), and the expanded cells are implanted into the full-thickness cartilage defect via a second procedure.

Indication contextUsed to repair symptomatic, full-thickness cartilage defects of the knee; evidence supports use for larger full-thickness defects

RehabilitationRequires patient willingness to comply with a vigorous post-procedure rehabilitation program

Definition — MACI (matrix-induced ACI) description

MACI descriptionMatrix-induced autologous chondrocyte implantation (MACI) uses autologous cultured chondrocytes seeded on a porcine collagen membrane (an autologous cellularized scaffold) to repair single or multiple symptomatic, full-thickness cartilage defects of the adult knee, with or without bone involvement.

Policy Summary

PayerMass General Brigham Health Plan

PolicyAutologous Chondrocyte Implantation (ACI) in the Knee

Policy CodePolicy 07

Change TypeAnnual updatematerial changes

Effective Date

Next Review Date

Key ActionTreating specialist must request prior authorization and submit documentation demonstrating age, BMI, defect size and location, symptom duration, and failed conservative therapy.

SourceLink

On This Page

Age range revised previously to allow up to age 55

Symptom duration — minimum required duration

Minimum symptom duration>= 6 months

Symptom descriptionSymptoms must interfere with activities of daily living

Documentation requirementClinical records must document duration and functional impact

BMI — body mass index eligibility requirement

BMI eligibilityBMI < 35 kg/m2

Effective changeBMI restriction added in August 2024 annual update

Documentation requirementLatest BMI should be documented in the clinical record

Denial Risk

Denial Triggers for Unmet Criteria

Requests that do not meet the plan's medical necessity criteria may be denied. Common denial triggers include: member age outside 15–55 years or skeletally immature adolescents without documented growth plate closure; BMI ≥ 35 kg/m2; cartilage defect size smaller than required threshold; defect location or etiology not consistent with criteria (e.g., non–weight-bearing areas or joints other than the knee); symptom duration less than six months; lack of documented failed conservative therapy; active knee infection; presence of osteoarthritis; or failure to obtain required prior authorization.

Age not within 15–55 years or no documentation of skeletal maturity for adolescents
BMI ≥ 35 kg/m2
Defect size below required threshold or inappropriate location
Symptoms present less than 6 months
No documentation of failed conservative therapies
Active knee infection or osteoarthritis (exclusion)
Prior authorization not obtained

Product typeCellularized scaffold product (porcine collagen membrane)

Allowed useExplicitly allowed by policy as an acceptable ACI method

Definition — Full-thickness chondral defect

Full-thickness definitionLesions that extend through to the subchondral bone

RelevanceCoverage limited to full-thickness chondral defects meeting size and location criteria

AssessmentDefect depth must be documented in operative or imaging reports to confirm full-thickness involvement