Abstract
Objective
The aim of this study is to both quantify and qualify the way insurance companies justify their coverage policies for autologous chondrocyte implantation (ACI) and determine whether these policies align with recent research on the subject.
Design
The top 11 national commercial health insurance payers for ACI were identified. Coverage policy documents were recovered for 8 payers. These documents were examined, and the type of reference and the level of evidence (LOE) were recorded for each applicable reference. Specific coverage criteria for each individual payer were then extracted and assessed for similarities among commercial payers. Finally, all references cited by each payer were examined to determine whether they mentioned the specific payer criteria.
Results
This study found that the majority of cited references were primary journal articles (86, 58.1%) and that only 30 (20.2%) references were level I or level II evidence. This study also found significant homogeneity among payer coverage criteria. Cited sources inconsistently mentioned specific payer coverage criteria. In addition, payer criteria tended to be poorly supported by current evidence on ACI.
Conclusions
This study demonstrates that commercial insurance payers’ coverage policies for ACI poorly cite references, cite a majority of references with low LOE, and cite references which infrequently mention their specific coverage criteria. In addition, payer coverage policies have a high degree of homogeneity and many of their specific criteria are poorly supported by current research on ACI.
Keywords
Introduction
Articular cartilage injures are a common knee injury, especially in those undergoing arthroscopy. It has been reported that 60% to 66% of knees undergoing arthroscopy have defects of the articular cartilage. 1 There are a multitude of different surgical procedures used to treat cartilage deficits, including chondroplasty, microfracture (MF), autologous chondrocyte implantation (ACI), and osteochondral allograft/autograft, with an overall average yearly incidence of 7.8 per 10,000 patients from 2007 to 2016. 2 There has been an overall decrease in the amount of cartilage procedures in that time frame, but this came mostly from the decrease in chondroplasty, while the incidence of MF and ACI has remained the same. 2 ACI involves a 2-stage procedure in which the patient’s own healthy chondrocytes are biopsied from a non-weightbearing portion of the joint, and then these cells are expanded ex vivo and later implanted back into the knee at the site of the lesion during the second stage. 3 A newer generation of the procedure is matrix-induced autologous chondrocyte implantation (MACI). MACI involves a similar biopsy procedure as ACI; however, the chondrocytes are implanted in a collagen scaffold, which is then reintroduced into the knee. 4
ACI is most commonly used for cartilage lesions in the knee, although further research is being conducted on its utility in other joints such as the ankle, hip, and shoulder.5-8 ACI has shown positive outcomes regardless of etiology of the defect, with the most common being acute trauma, chronic trauma, and osteochondritis dissecans (OCD). 3 While MF is more commonly used, 2 studies on ACI versus MF have shown ACI to have no difference and sometimes even improvement in patient-reported outcome measures (PROMs) when compared with MF, as well as improved failure rates, quality of life, and pain relief.9,10 Literature has also demonstrated the efficacy of ACI over osteochondral autograft transfer (OAT). 11 There is strong evidence supporting the benefit of ACI/MACI in the knee in a wide range of sub-populations.12-14
ACI is an expensive procedure, costing approximately $10,000 to $15,000.15,16 Most patients rely on insurance payers to cover this costly procedure; however, many payers employ restrictive criteria in their coverage policies, which make it difficult for patients and physicians to get authorization for these procedures. As commercial payers lack the power to retrospectively demand repayment for unnecessary procedures, they often prospectively limit access in an attempt to control cost. This can lead to delays in treatment, possibly resulting in worsening of the patients’ conditions, and lead to both patient and physician dissatisfaction and frustration. As discussed above, ACI has thus far shown to be as effective, if not superior, to MF in recent comparative studies, but it continues to remain unauthorized by insurance payers.
In many instances, coverage criteria are supported by vague or tenuous scientific evidence. There have been previous studies demonstrating the low quality of evidence used by payers’ criteria in other procedures. Austin et al. (2021) investigated the level of evidence (LOE) of coverage policies in total joint arthroplasty (TJA) and found that a majority of the references had low LOE and poor applicability to the TJA patient population. Sudah et al. (2023) investigated the LOE for shoulder arthroplasty policy and found similar results. To the knowledge of the authors, no prior study has investigated the quality of evidence in payers’ criteria for ACI/MACI coverage policies.
The aim of this study is to both quantify and qualify the manner in which insurance companies justify their coverage policies for ACI and determine whether these policies align with recent research on the subject. The hope is that this study can help physicians better understand ACI coverage criteria and the evidence used to support them to deliver more well-informed, efficient care. It was hypothesized that payers overall would cite references inconsistently, utilize low LOE sources, and insufficiently support their individual coverage criteria.
Methods
Payer Selection
This study was a qualitative review of insurance payer coverage policy references. There were 8 insurance companies (Aetna, Anthem, Centene, Cigna, Health Care Services Corp [HCSC], Highmark, Humana, and United Healthcare) identified for this study that had publicly accessible policies for ACI/MACI. Other non-publicly accessible policies (including Kaiser, UMPC) were attempted to be accessed by phone with no success. Coverage policy documents were secured for each payer.17-23 All sources specifically cited within the text of the policy were included for analysis.
Screening
To identify additional studies relevant to ACI or MACI in the references of the coverage documents, titles were screened for the following terminology: “Autologous chondrocyte/cartilage implantation/transplantation” OR “Matrix-assisted/associated/induced autologous chondrocyte implantation/transplantation.” The equivalent acronyms of ACI or MACI were also included. Only studies that evaluated efficacy of the procedure in the knee joint were included. Ankle, hip, and shoulder studies were excluded. A total of 6 studies were removed due to mention in the experimental/uncovered section of the payers’ policies.
Data Collection
Data were collected independently by 2 authors (EL and JK), with discrepancies resolved by a third (AF). Data were collected in the months of September and October of 2023. For each study, the type of reference and the LOE were recorded. 24 The categories for type of reference included the following: primary journal article, review, government guidelines/documents, society guideline, website, miscellaneous, and could not be found. The LOE categories included levels I-V, N/A, and inability to evaluate.
Evaluation of Coverage Criteria
Each study was reviewed to see whether they mention individual payer criteria. These criteria included size of lesion, location of lesion, number of lesions, presence of bipolar/kissing lesions, presence of intact meniscus, use of Kellgren-Lawrence Grading System, alignment of joint, age, body mass index (BMI) <35, failure of conservative therapy (2 or 3 months), Outerbridge Grade, presence of inflammatory/rheumatoid arthritis, limitation of daily activities, stability of knee, ligamentous stability, joint space, subchondral bone involvement, responsiveness to past surgical repair, etiology of defect, and informed consent. These criteria overlapped to cover all criteria that were mentioned in the payers’ policies. For reviews, if any of the summaries of the articles mentioned in the review studied the aforementioned criteria, the review was considered to have investigated those criteria.
Statistics
The statistics for this study were largely descriptive. The frequency of each reference type and LOE were calculated per payer and overall as both a count and a percentage. Articles that were cited in multiple payer policies were counted and noted and statistics were completed both with and without these duplicates. The number of excluded ankle/hip/shoulder studies were noted when applicable. The frequency of each coverage criteria mentioned in each of the articles was calculated as a count and as a percentage. The number of studies per payer that mentioned at least one of the coverage criteria was calculated as a percentage.
Results
After reviewing the references of 8 payers on ACI and MACI, including Aetna, Anthem, Centene, Cigna, Health Care Services Corp, Highmark, Humana, and United Healthcare, there were 187 articles that met the inclusion criteria and 148 total when excluding duplicates across companies. Of the 148 unique articles, 86 (58.1%) were primary journal articles, 31 (20.9%) were reviews, 14 (8.4%) were government guidelines, 10 (6.8%) could not be found, 4 (2.7%) were websites, 2 (1.4%) were miscellaneous, and 1 (0.7%) was a society guideline
Reference Types by Payer and in Sum.
Reference Level of Evidence by Payer and in Sum.
Inclusion of Common Coverage Criteria by Commercial Payer.
References Cited in at Least 3 or More Different Insurance Payers.
Aetna
Aetna had the most total articles that met criteria for this study with 88 articles, with 63.6% being primary journal articles and 21.5% being level I or II studies (
Aetna has 12 criteria listed on their website policy which are listed in Table 5 . In all, 17.1% of articles mentioned at least one of the criteria in the study. The size of the defect in depth, length, and area were not studied by any of the primary journal articles. Only 2 of the primary journal articles discussed failure of conservative therapy with a minimum of 2 months of physical therapy prior to the procedure.
Number and Percent of References Cited by Each Payer That Mention Their Specific Coverage Criteria.
Anthem
Anthem’s coverage criteria for ACI are listed in a document entitled “Appropriate Use Criteria: Joint Surgery.” There are many references listed at the end of the document; however, none are applicable to ACI patients. Anthem’s criteria for ACI coverage can be found in
Centene
Centene had in-text citations for 3 articles in their ACI coverage policy. Of these 3, only 1 was on the topic of ACI. In total, Centene had 7 articles that met the criteria for this study. Of the 7, 2 (28.6%) were primary journal articles, with 0 level I studies and 2 (28.6%) level II studies (
Centene’s coverage criteria for ACI are listed in
Cigna
Cigna had 10 studies included for analysis none of which were cited within the main text of the coverage document. Of the 10, 7 (70%) were primary journal articles
Cigna has 2 criteria in its policy for ACI listed in Table 5 . 30% of references investigated at least one of the policies.
Health Care Service Corporation
HCSC had 22 studies included in this study all of which were cited in the main text of the coverage document. Of the 22, 16 (72.7%) were primary journal articles and 5 (22.7%) were reviews
HCSC has 9 criteria in its policy for ACI listed in Table 5 . In all, 34% of references investigated at least one of the policies. All criteria were investigated by at least one article.
Highmark
Highmark had 29 studies that met criteria for this study. None of these studies were cited in the main text of the coverage policy. Of the 29, 21 (72.4%) were primary journal articles and 5 (17.4%) were reviews
Highmark has 11 criteria in its policy for ACI listed in Table 5 . In all, 21% of references investigated at least one of the criteria. All criteria were investigated by at least one article.
Humana
Humana had 9 studies that met criteria for this study, of which none were cited in the main text. Of the 9, 2 (22.2%) were primary journal articles, 2 (22.2%) were websites, and 5 (55.6%) could not be found
Humana has 11 criteria in its policy for ACI listed in Table 5 . In all, 6% of references investigated at least one of the criteria. Many of the criteria went uninvestigated including absence of contraindications, BMI <35, failure of conservative treatment, smoking cessation plan for smokers, and previous surgical repair greater than 6 months prior to transplantation.
United
United had 22 studies that met criteria for this study. Of the 22, 7 (31.2%) were primary journal articles and 8 (36.4%) were reviews
United has 6 criteria in its policy for ACI listed in Table 5 . In all, 15.9% of studies investigated at least one of the criteria. The only criterion that was not studied across the cited articles was the size and nature of the lesion.
Discussion
By analyzing the references that commercial insurance payers cite in their coverage policies for ACI, this study found that the majority of references are primary journal articles (58.1%)
These findings are consistent with prior research in the total joint and total shoulder arthroplasty literature.30,31 A 2021 study by Austin et al. reviewed 282 references in coverage policies for total joint arthroplasty procedures and found that 45.8% were primary journal articles and 14.2% were level I or II evidence. They also found that only 41.2% were applicable to total joint arthroplasty candidates. 30 Another 2023 study by Sudah et al. analyzing 118 references supporting coverage criteria for total shoulder arthroplasty demonstrated primary journal articles (59.3%) were the most prevalent article type and that only 5.2% of cited studies were level I or II evidence. This finding of lower quality references in ACI appears to be reflective of an overall trend of poor evidence across coverage policies of other orthopedic procedures. It is unclear why poorer quality studies continue to be cited, but because it is consistent across other procedures, it is possible that the insurance payers tend to select articles more in line with their policies while sacrificing quality. Lobbying by physicians and patients to improve quality of evidence in these policies would be a first step to improving the decision-making in these policies and in the clinical setting.
Beyond citing references poorly and consistently citing low LOE research, careful examination of the common commercial insurance coverage criteria for ACI reveals that while some are supported by current research on the subject, many are poorly substantiated, outdated, or overly restrictive. Of the 8 companies analyzed, 5 (Aetna, Centene, HCSC, Highmark, and Humana) have a criterion specifying that patients’ BMI be less that 35 kg/m2 to have ACI covered by insurance. This is supported by research demonstrating poor efficacy in obese patients undergoing ACI. A study found that Modified Cincinnati scores (MCS) were worse at 2 years postoperatively (30.6) compared with preoperatively (33.7) in patients with a BMI >30 kg/m2. 32
Unlike BMI, however, other criteria are poorly supported. Five (Aetna, Centene, HCSC, Highmark, and Humana) companies have a criterion that requires patients to have failed either 2 or 3 months of conservative therapy. None of the references cited by payers specifically investigated the efficacy of conservative, non-operative treatment modalities for cartilage deficits, despite many of the payers requiring failure of conservative therapy. Of the cited studies that mention failure of conservative treatment, few give specific therapies failed, and fewer give specific lengths of time for failed therapy. A 2010 systematic review by Harris et al. 33 found that patients with shorter preoperative duration of symptoms had better outcomes after ACI. Another 2021 study by Pettit et al. 34 found that defect expansion increased 0.11 cm2 (standard error = 0.03) per month delay to ACI (P = 0.001). Given that literature demonstrates a longer duration of symptoms is associated with worse outcomes after ACI and that defects tend to expand over time, having strict criteria of at least 2 or 3 months of conservative therapy may actually be harming patients.
Of the payers analyzed, all 8 provide coverage for lesions on the femoral condyles; however, only 6 (Aetna, Anthem, HCSC, Highmark, Humana, and United Healthcare) cover patellar defects. By failing to cover patellar lesions, Cetene and Cigna place a unique restriction on which patients are eligible for ACI. Prior research has shown ACI to provide good outcomes in the treatment of patellar chondral defects. A 2014 study by Gomoll et al. which included 110 patients undergoing ACI for patellar lesions found significant increases in International Knee Documentation Committee (IKDC), MCS, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores (P < 0.0001 for all). They also found that 92% of patients would undergo the same procedure again and that 86% of patients rated their knee function as good or excellent postoperatively. 35 Another study investigating ACI in 30 patients with patellar lesions found that at 2 to 14 years postoperatively, 83% of patients rated their knee function as good to excellent. 36 Finally, a study of 58 patients with bipolar lesions of the patellofemoral compartment that underwent ACI found survival to 79% at 10 years. 37 At a mean follow-up of 8.8 ± 4.2 years, they also found significant increases in the MCS, WOMAC, and visual analogue scale (VAS) scores as well as an 88% patient satisfaction rating of “very high.” Not only does this study providence evidence to support coverage of ACI for patellar lesions, but it also supports the use of ACI for bipolar lesions of the patellofemoral compartment. Three payers (Aetna, HCSC, and Humana) will not cover ACI in the presence of a bipolar cartilage lesion. This is yet another example of strict criteria in which existing literature does not support.
The articles cited in Table 4 can be used as an alternate overview of the effectiveness of ACI/MACI. A 2017 study by Ebert et al. 38 was the most commonly cited article across the payers, and discusses that there was actually no significant difference in outcomes between MACI in the patellofemoral joint and in the femoral condyles, further supporting the use of MACI in patellar lesions. A study by Saris et al. 39 was a randomized controlled trial that showed clinical and statistically significant improvement with MACI over MF in symptomatic cartilage defects greater than or equal to 3 cm2. A review by Harris et al. 33 shows generalized short-term success for cartilage procedures, citing patient-specific factors that would influence clinical outcome. The study by Nawaz et al. 40 showed MACI and ACI both had relatively good results at 5 and 10 years. Last, a review by Mistry et al. 41 showed equivalent cost-effectiveness between ACI and MF, but emphasized the need for long-term results for newer generations of ACI. These findings are intriguing given that nearly all of them support the use of ACI/MACI in different capacities, yet insurance payers continue to make it difficult to be approved for the procedure. They have cited studies demonstrating patient/lesion-specific factors play a role in determining clinical outcome, yet strict coverage criteria limit the flexibility clinicians have to perform these procedures. These strict coverage criteria can result in delays in treatment as patients and physicians attempt to navigate through the decision process of payers. Delays in treatment of cartilage defects result in worsening of conditions and poorer outcomes, even after surgical intervention,33,34 further emphasizing the importance of timely intervention and adhering to these strict criteria.
Clinically, this study recommends clinicians be aware of the coverage criteria and the evidence that payers use to support the criteria. This article can be utilized by clinicians in peer-to-peer review as evidence for poor quality of evidence supporting ACI/MACI coverage policies. Clinicians should also educate their patients regarding criteria, setting expectations regarding the treatment options. Insurance payers should be encouraged to adjust their policies given the lower level of studies they have cited. As demonstrated, there are higher level papers that can be cited showing the benefits of ACI in patient populations that are not covered by many of the payers, as well as evidence that ACI is more effective than the more popularly used MF and osteochondral autograft transplantation (OATS). Continual research should continue to be done for ACI/MACI to improve the body of literature available to support coverage policies. Decreasing the cost of the procedure and studying long-term effects are 2 areas that should be targeted for ACI.
This study was not without limitations. First, coverage policies were not able to be identified for 3 insurance providers (Kaiser Permanente, the UPMC Health Plan, and WellCare Health Plans). As mentioned in the methods section, these nonpublicly accessible policies were contacted by phone, but the policy could not be provided. This may hurt the generalization of this study given that Kaiser is one of the larger payers in the country. Nevertheless, the 8 included payers cover more than 200 million patients in the United Status and thus the results are applicable to a large percentage of the country’s population. 42 Second, 5 articles were not able to fully be accessed, which limited the ability to comment on their content; however, this represented a small percentage of the total references and full access would likely not have substantially altered the findings in this study.
Conclusion
This study demonstrates that commercial insurance payers’ coverage policies for ACI poorly cite references, cite a majority of references with low LOE, and cite references which infrequently mention their specific coverage criteria. In addition, payer coverage policies have a high degree of homogeneity and many of their specific criteria are not supported by current research on ACI. It is thus possible that there are many patients that might benefit from ACI that would be denied insurance coverage without proper justification.
Footnotes
Acknowledgment and Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Ethical Approval
Not applicable.
