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Cost-Effectiveness Analysis of Needle Arthroscopy Versus Magnetic Resonance Imaging in the Diagnosis and Treatment of Meniscal Tears of the Knee

      Purpose

      To determine whether needle arthroscopy (NA) compared with magnetic resonance imaging (MRI) in the diagnosis and treatment of meniscal tears is cost-effective when evaluated over a 2-year period via patient-reported outcomes. The hypothesis is that improved diagnostic accuracy with NA would lead to less costly care and similar outcomes.

      Methods

      A Markov model/decision tree analysis was performed using TreeAge Pro 2017 software. Patients were evaluated for degenerative and traumatic damage to the lateral/medial meniscus. Assumed sensitivities and specificities were derived from the medical literature. The direct costs for care were derived from the 2017 Medicare fee schedule and from private payer reimbursement rates. Costs for care included procedures performed for false-positive findings and for care for false-negative findings. Effectiveness was examined using the global knee injury and osteoarthritis outcome score (KOOS). Patients were evaluated over 2 years for costs and outcomes, including complications. Dominance and incremental cost-effectiveness were evaluated, and 1- to 2-way sensitivity analysis was performed to determine those variables that had the greatest effect. The consolidated economics evaluation and reporting standards checklist for reporting economic evaluations was used.

      Results

      NA was less costly and had similar KOOS versus MRI for both the medial/lateral meniscus with private pay. Costs were less for both Medicare and private pay for medial meniscus, $780 to $1,862, and lateral meniscus, $314 to $1,256, respectively.

      Conclusions

      Based on the reported MRI incidence of false positives with the medial meniscus and false negatives with the lateral meniscus and based on assumed standards of care, more costly care is provided when using MRI compared with NA. Outcomes were similar with NA compared with MRI.

      Level of Evidence

      Level II, economic and decision analysis.
      Magnetic resonance imaging (MRI) is the predominant diagnostic modality in assessing soft tissue knee pathology. One of the main issues with the use of MRI is the rate of false positive (FP) and false negative (FN) findings,
      • Hardy J.C.
      • Evangelista G.T.
      • Grana W.A.
      • et al.
      Accuracy of magnetic resonance imaging of the knee in the community setting.
      • Lee C.S.
      • Davis S.M.
      • McGroder C.
      • et al.
      Analysis of low-field magnetic resonance imaging scanners for evaluation of knee pathology based on arthroscopy.
      which may result in unnecessary arthroscopic surgeries (for FPs) or in the delay of therapies (for FNs) for pain relief.
      Arthroscopy is the gold standard against which other imaging technologies are compared.
      • Nickinson R.
      • Darrah C.
      • Donell S.
      Accuracy of clinical diagnosis in patients undergoing knee arthroscopy.
      However, arthroscopy is rarely used as a diagnostic tool and has been replaced by MRI.
      Recently introduced, needle arthroscopy (NA) has demonstrated equivalent accuracy to standard arthroscopies in the diagnosis of meniscal
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      • Diermengian C.A.
      • Dines J.S.
      • Verance J.V.
      • et al.
      Use of a small-bore needle arthroscopy to diagnose intra-articular knee pathology: Comparison with magnetic resonance imaging.
      and femoral condylar lesions.
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      Some of the advantages in using NA in the physician's office are convenience and immediacy of diagnosis as it can be performed as part of an initial patient visit.
      • McMillan S.
      • Schwartz M.
      • Jennings B.
      • et al.
      In-office diagnostic needle arthroscopy: Understanding the potential value for the US healthcare system.
      The purpose of this analysis is to determine whether NA compared with MRI in the diagnosis and treatment of meniscal tears is cost-effective when evaluated over a 2-year period via patient-reported outcomes. The hypothesis is that improved diagnostic accuracy with NA would lead to less costly care and similar outcomes.

      Methods

      Literature searches were performed on November 9 and 10, 2017, using the following search terms in PubMed: ((((Quality) AND Life) AND Instruments) AND arthroscopy) AND knee (11 articles identified; 2 articles obtained); PubMed: (((MRI) AND knee) AND quality) AND life (95 articles identified; 6 articles obtained); PubMed: (((knee) AND arthroscopy) AND cost) AND effectiveness (62 articles identified; 4 articles obtained); EBSCO: Quality of Life AND knee AND arthroscopy (100 articles identified; 4 articles obtained).
      The base case population evaluated middle-age (mid to late 40s to the early 50s) adults with intra-articular knee damage (medial and/or lateral meniscal damage) presenting with symptoms indicative of a meniscal lesion, who were not contraindicated to completing an MRI, who did not have an infection, and who presented to an orthopaedic physician specializing in arthroscopy with knee pain for several months. Based on clinical work-up, an MRI versus in-office diagnostic NA was indicated. A decision to treat or not was made on the MRI or NA diagnosis.

      Modeling the Condition

      TreeAge Pro 2017 Markov modeling software was used to evaluate the cost and effectiveness of NA versus MRI in the diagnoses and subsequent treatment based on the findings of both diagnostic modalities based on results in the medical literature. TreeAge Pro is a decision support model accepted by such organizations as the National Institutes for Health and Clinical Excellence (United Kingdom).
      • Davis S.
      • Stevenson M.
      • Tappenden P.
      • Wailoo A.J.
      NICE Decision support unit technical support document 15: Cost-effectiveness modelling using patient-level simulation.

      Diagnoses and Treatment(s)

      The following diagnoses were evaluated: medial and lateral meniscus pathology. Treatment for each condition occurred for true positive (TP) and FP for both NA and MRI findings. For meniscus pathology it was assumed that a partial meniscectomy (medial or lateral; CPT 29881) was performed in symptomatic patients without severe degenerative knee pathology and that subsequent follow-up care provided including physical therapy. The reason a partial meniscectomy was chosen was for simplicity's sake and owing to the fact that it is the dominant procedure performed. True negative (TN) findings were not treated, and it was assumed the patient had no follow-up clinical care. FN findings were followed up with physical therapy first and, if this failed, hyaluronic acid (HA) injections were administered.

      Viscosupplementation for osteoarthritis. Blue Cross Blue Shield of Illinois. Health Care Services Corporation. Policy #RX501.049. Effective: July 15, 2017.

      Viscosupplementation for osteoarthritis. CIGNA policy #1405. Effective: June 15, 2017.

      Viscosupplementation of the knee. Aetna policy #0179. Next review: February 8, 2018.

      HA was administered if patients were in pain or had degenerative disease (e.g., early-stage osteoarthritis); HA treatments are found to be the safest and longest lasting for lowering the pain.
      • Bowman S.
      • Awqad M.E.
      • Hamrick M.W.
      • et al.
      Recent advances in hyaluronic acid based therapy for osteoarthritis.
      This treatment paradigm attempted to follow current practice patterns, coverage policies of the major private payers, and appropriate use criteria.
      • Bhadra A.K.
      • Altman R.
      • Dasa V.
      • et al.
      Appropriate use criteria for hyaluronic acid in the treatment of knee osteoarthritis in the United States.
      If these failed, patients went on to surgery (CPT 29881). The sensitivities and specificities used in the Markov model are found in Table 1.
      Table 1Sensitivities/Specificities (%) Used in the Markov Model
      ConditionNeedle ArthroscopyMagnetic Resonance Imaging
      Medial meniscus95/97
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      90/81
      • Crawford R.
      • Walley G.
      • Bridgman S.
      • et al.
      Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: A systematic review.
      Lateral meniscus93/90
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      75/94
      • Crawford R.
      • Walley G.
      • Bridgman S.
      • et al.
      Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: A systematic review.

      Inputs

      Evaluation of Outcomes

      Outcomes for patients undergoing therapy (or not) for suspected knee damage were evaluated for effectiveness using the knee injury and osteoarthritis outcome score (KOOS). KOOS is an instrument mainly used for evaluating osteoarthritis but has also been validated for knee injury.
      • Roos E.M.
      • Lomander L.S.
      The knee injury and osteoarthritis outcome score (KOOS): From joint injury to osteoarthritis.
      KOOS4 (mean score for four of five KOOS subscale scores: pain, other symptoms, function in sport and recreation, and knee related quality of life) was used in the model to evaluate the various outcome states the patient exhibited over a 2-year period from baseline. KOOS scores at each time frame were then totaled for an aggregate outcome score. Appendix Table 1 shows the relevant KOOS4 values used in the Markov model at baseline and 1 and 2 years. Outcomes were discounted at 3%.
      • Gold M.R.
      • Siegel J.E.
      • Russell L.B.
      • et al.
      Cost-effectiveness in health and medicine.

      Evaluation of Costs

      The direct costs for diagnosis and treatment were based on the 2017 Medicare national average fee schedule and are found in Appendix Table 1. MRI and NA private payer reimbursement rates were based on available data.
      • Cooper Z.
      • Craig S.V.
      • Gaynor M.
      • Van Reenen J.
      The price ain’t right? Hospital prices and health spending on the privately insured.
      Private payment rates were based on an assumed premium of 30% over Medicare rates. Surgical procedures were assumed to take place in the hospital outpatient setting. MRI was assumed to take place in the hospital outpatient setting as well (CPT 73721 + APC 5523; $240 + $219 = $459 for Medicare

      Centers for Medicare & Medicaid Services. 2017 National average payment rates for Medicare (obtained via search). https://www.cms.gov/apps/physician-fee-schedule/license-agreement.aspx.

      and $1,628 for private pay
      • Cooper Z.
      • Craig S.V.
      • Gaynor M.
      • Van Reenen J.
      The price ain’t right? Hospital prices and health spending on the privately insured.
      ) or in a freestanding MRI facility (private pay at $1,050).
      • McMillan S.
      • Schwartz M.
      • Jennings B.
      • et al.
      In-office diagnostic needle arthroscopy: Understanding the potential value for the US healthcare system.
      NA was assumed to take place in the physician office setting and was reimbursed using CPT 29870 ($598 for Medicare

      Centers for Medicare & Medicaid Services. 2017 National average payment rates for Medicare (obtained via search). https://www.cms.gov/apps/physician-fee-schedule/license-agreement.aspx.

      and $958 for private pay [Data on file: VisionScope Technologies]). The costs of performing CPT 29870 in the physician office setting are included in CPT 29870 and reflect such expenses as needle arthroscope, cost of the dressing/injection/anesthetic, cost of administration and preparation of the medication and the room (practice expenses), and the time to perform the procedure (physician work). All of these costs are embedded in the relative value units for both physician work and practice expense.

      Centers for Medicare & Medicaid Services. Details for title: CMS-1654-F. https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/PhysicianFeeSched/PFS-Federal-Regulation-Notices-Items/CMS-1654-F.html. Accessed September 4, 2018.

      Additionally, it was assumed that the patient population would represent a typical enrollee of either private insurer or Medicare. Complications were also factored into surgical procedures and included deep vein thrombosis, pulmonary embolism, venous thromboembolism, and any other complication requiring a patient be admitted to the hospital. These costs and their incidence were derived from the medical literature.
      • Lin J.
      • Preblick R.
      • Lingohr-Smith M.
      • et al.
      Incremental health care resource utilization and economic burden of venous thromboembolism recurrence from a US payer perspective.
      • Spyropoulos A.C.
      • Lin J.
      Direct medical costs of venous thromboembolism and subsequent hospital readmission rates: An administrative claims analysis from 30 managed care organizations.
      Costs were discounted at 3%.
      • Gold M.R.
      • Siegel J.E.
      • Russell L.B.
      • et al.
      Cost-effectiveness in health and medicine.

      Running the Model

      Based on the probability of a finding of a TP or FP, patients were surgically treated and corresponding health states were assumed postprocedure relating to complications, rehabilitation, and outcome. For FN findings, it was assumed patient first underwent physical rehabilitation. If this failed, patients underwent HA injections, and if those failed, they ultimately underwent surgery

      Viscosupplementation for osteoarthritis. Blue Cross Blue Shield of Illinois. Health Care Services Corporation. Policy #RX501.049. Effective: July 15, 2017.

      Viscosupplementation for osteoarthritis. CIGNA policy #1405. Effective: June 15, 2017.

      Viscosupplementation of the knee. Aetna policy #0179. Next review: February 8, 2018.

      • Gauffin H.
      • Tagesson S.
      • Meunier A.
      • et al.
      Knee arthroscopic surgery is beneficial to middle-aged patients with meniscal symptoms: A prospective, randomised, single-blinded study.
      • Mather R.C.
      • Garrett W.E.
      • Cole B.J.
      • et al.
      Cost-effectiveness analysis of the diagnosis of meniscal tears.
      Figure 1 shows the Markov model for diagnosis and treatment for the medial meniscus. Figure 2 shows the structure for Markov state transition diagram for an FP finding. One- and 2-way sensitivity analyses were performed to determine which variables had the greatest effect on overall cost for care. Each variable was varied at least ±25% to determine strength of the findings and to determine the point at which MRI or NA was the preferred diagnostic based on overall costs. Incremental cost effect scatterplot analysis using Monte Carlo simulation (sampling probabilistic sensitivity, run 10,000 times) was performed to determine the percentage of time therapies that were dominant (resulted in overall lower cost with improved outcomes) for each condition. All probabilities of events occurring are identified in Appendix Table 1 for medial meniscus pathology. Four different Markov models were developed: medial and lateral meniscus (using Medicare or private pay information) with appropriate therapeutic follow-up. These models differed slightly based on specificities and sensitivities for MRI and NA (as per Table 1) and for surgical therapy for meniscal damage as well.
      Figure thumbnail gr1
      Fig 1Decision tree comparing use of needle arthroscopy to magnetic resonance imaging as a diagnostic prior to surgery.
      Figure thumbnail gr2
      Fig 2Transition state diagram of a false positive magnetic resonance imaging finding and resultant care based on that finding.
      Last, the consolidated economics evaluation and reporting standards checklist
      • Husereau D.
      • Drummond M.
      • Petrou S.
      • et al.
      Consolidated health economic evaluation reporting standards (CHEERS)—Explanation and elaboration: A report of the ISPOR health economic evaluations publication guidelines good reporting practices task force.
      was used to ensure recommended items were included in the economic evaluation (Appendix Figure 1).

      Results

      Baseline 2-year costs and outcomes derived from each Markov model for Medicare and for private pay are shown in Tables 2 and 3.
      Table 2Medicare
      ConditionNA (Costs/KOOS4)Magnetic Resonance Imaging (Costs/KOOS4)Cost Savings With NACost-Effectiveness
      Medial meniscus3,996/1874,776/185780NA dominant
      Lateral meniscus2,324/2062,638/201314NA dominant
      NOTE. All costs are in dollars.
      KOOS, knee injury and osteoarthritis outcome score; NA, needle arthroscopy.
      Table 3Private Payer Payment Rates
      ConditionNA (Costs/KOOS4)Magnetic Resonance Imaging (Costs/KOOS4)Cost Savings With NACost-Effectiveness
      Medialmeniscus5,361/1877,223/1851,862NA dominant
      Lateral meniscus3,193/2064,449/2011,256NA dominant
      NOTE. All costs are in dollars.
      KOOS, knee injury and osteoarthritis outcome score; NA, needle arthroscopy.
      Appendix Table 2 shows each of the stages (years 0 to 2; with “0” being the initial encounter/procedure) and state transitions for NA and MRI for TP, FP, TN, and FN findings. Each of these stages has an associated probability of occurring, an associated cost, and outcome as measured by KOOS4. The values identified in Appendix Table 2 are for a medial meniscus tear using Medicare costs. Furthermore, each of the TPs, FPs, TNs, and FNs also has an associated probability of occurring based on the literature.
      • Roos E.M.
      • Lomander L.S.
      The knee injury and osteoarthritis outcome score (KOOS): From joint injury to osteoarthritis.
      • Kijowski R.
      • Blankenbaker D.G.
      • Woods M.A.
      • et al.
      3.0-T evaluation of knee cartilage by using three-dimensional IDEAL GRASS imaging: Comparison with fast spin-echo imaging.
      The incremental cost-effectiveness (ICE) scatterplots in Monte Carlo simulation with respect to NA versus MRI dominance using Medicare data are summarized in Table 4 and in Figure 3 (used as an example of an ICE scatterplot). ICE scatterplots in Monte Carlo simulation showed that with private pay rates, NA was dominant to MRI the majority of the time (Table 5). Two-way sensitivity analysis demonstrated that at various costs for both MRI and NA, NA was the less costly alternative in the majority of cases (Table 6). One-way sensitivity demonstrated that the following variables and thresholds affected the model, resulting in a lower cost for MRI versus NA based on Medicare payment amounts (Table 7) and private pay payment amounts (Table 8): cost of NA, cost of MRI, percentage of MRI positives, and percentage of NA positives. Note that all parameters/ranges used can be found in Appendix Table 1 for Medicare (medial meniscus only) and Appendix Table 3 for private pay (medial meniscus only).
      Table 4Medicare Data
      ConditionNeedle Arthroscopy Dominant % of TimeMagnetic Resonance Imaging Dominant % of TimeICER Ratio for NA
      Medial meniscus619N/A
      Lateral meniscus805N/A
      ICER, incremental cost effectiveness ratio; N/A, not applicable.
      Figure thumbnail gr3
      Fig 3Medial meniscus Medicare incremental cost-effectiveness scatterplot examining the probabilities of incrementally lower or higher costs and knee injury and osteoarthritis outcome scores in using needle arthroscopy versus magnetic resonance imaging.
      Table 5Private Payer Data
      ConditionNeedle Arthroscopy Dominant % of TimeMagnetic Resonance Imaging Dominant % of TimeICER Ratio for NA
      Medial meniscus642.8N/A
      Lateral meniscus861.2N/A
      ICER, incremental cost effectiveness ratio; N/A, not applicable.
      Table 6Two-Way Sensitivity
      ConditionDifference in Cost for MRI to Be Preferred
      Medial meniscusNA >$919 more costly than MRI ($1,378 less $459); NA is the less costly alternative.
      Lateral meniscusNA >$453 more costly than MRI ($912 less $459); NA is the less costly alternative.
      MRI, magnetic resonance imaging; NA, needle arthroscopy.
      Table 7One-Way Sensitivity Analysis of Variables that Most Affected the Markov Model (Medicare)
      Variable (also Appendix Table 1)Medial MeniscusLateral Meniscus
      Cost of NA (CPT 29870) = $598>1,378>912
      Percentage of MRIs positive of MRIs performed (positive + negative findings)<43<21
      Percentage of NAs positive of all NAs performed (positive + negative findings)>54>24
      NOTE. Values above or below those shown resulted in either NA or MRI being the more costly option.
      MRI, magnetic resonance imaging; NA, needle arthroscopy.
      Table 8One-Way Sensitivity Analysis of Variables that Most Affected the Markov Model (Private Pay)
      Variable (also Appendix Table 3)Medial MeniscusLateral Meniscus
      Cost ($) of MRI (CPT 73721) (model assumes cost of $1,628 ± $622 [facility] and $1,050 [nonfacility]MRI always more expensive<371
      Cost ($) of NA (CPT 29870) (model assumes cost of $958 ± $317)>2,820>2,215
      Percentage of MRIs positive of MRIs performed (positive + negative findings)<35<11
      Percentage of NAs positive of all NAs performed (positive + negative findings)>63>33
      NOTE. Values above or below those shown resulted in either NA or MRI being the more costly option.
      MRI, magnetic resonance imaging; NA, needle arthroscopy.

      Discussion

      In analyzing the cost-effectiveness of NA using Markov modeling, NA was found to be less costly than MRI while providing for “equivalent/improved” outcomes. With private payers, MRI reimbursement for the lower limb without contrast, from a recent analysis surveying 1,584 hospitals (and from 3 large private insurers: Aetna, Humana, and United Healthcare), averaged $1,332 ± 509 (2011 data, inflated to 2017 using hospital outpatient medical CPI $1,628 ± $622).
      • Cooper Z.
      • Craig S.V.
      • Gaynor M.
      • Van Reenen J.
      The price ain’t right? Hospital prices and health spending on the privately insured.
      In contrast, internal data collected on CPT 29870 (diagnostic knee arthroscopy; physician office setting) for private payers (Aetna, BCBS, CIGNA, Humana, United Healthcare mainly in the following states: CA, CT, GA, IL, NJ, MA) estimated a reimbursement rate of $958 ± $317 (data available from VisionScope Technologies and consistent with Truven data, $1,175). When using these values in the models, NA dominated MRI.
      For this analysis, it was assumed that an MRI for a private pay patient would be performed in the hospital outpatient setting, where reimbursement is highest, $1,628. This is compared with an approximate $1,050 reimbursement rate for an MRI performed in a freestanding MRI facility.
      • McMillan S.
      • Schwartz M.
      • Jennings B.
      • et al.
      In-office diagnostic needle arthroscopy: Understanding the potential value for the US healthcare system.
      If the MRI value of $1,050 were used in the analysis, NA still would be the least costly in all lesions examined with savings of $1,284 (medial meniscus) and $678 (lateral meniscus). In other words, no matter the setting for an MRI under private pay, NA was the least costly alternative and provided for “equivalent/improved” outcomes. Although the reimbursement rate for MRI and NA may vary across the United States based on negotiated rates between providers and insurers, the private pay reimbursement rates for NA and MRI in this analysis were derived from large data sets and from large payers (Data on file: VisionScope Technologies; Truven 2017 data). In a separate sensitivity analysis of the cost of an MRI (Table 8), the following MRI private pay reimbursements would need to be met for MRI to be the less costly alternative: for the medial meniscus, NA is always the less costly alternative no matter the MRI reimbursement (ranges evaluated in sensitivity analysis $0 to $3,000); for the lateral meniscus, MRI would need to be <$371 (Fig 4).
      Figure thumbnail gr4
      Fig 4Sensitivity analysis of cost of magnetic resonance imaging (private pay rate) in evaluating a lateral meniscus lesion.
      In all clinical scenarios, NA produced superior outcomes versus MRI as measured by KOOS4. The KOOS4 scores as evaluated in this analysis assumed a given treatment paradigm (e.g., all FPs were treated with surgical arthroscopy, and all FNs were treated via surgical arthroscopy if PT and HA injections were first not successful), which may not be the case in actual practice. Specifically, some clinicians may not treat FP findings and FN findings may not deteriorate to the point of requiring an intervention. Thus, the KOOS4 outcomes findings herein may be subject to debate.
      Gill et al.
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      published the accuracies (sensitivities and specificities) used in the model. These accuracies were in line with other studies.
      • Diermengian C.A.
      • Dines J.S.
      • Verance J.V.
      • et al.
      Use of a small-bore needle arthroscopy to diagnose intra-articular knee pathology: Comparison with magnetic resonance imaging.
      • Gramas D.A.
      • Antounian F.S.
      • Peterfy C.G.
      • et al.
      Assessment of needle arthroscopy, standard arthroscopy, physical examination, and magnetic resonance imaging in knee pain: A pilot study.
      It should also be noted that in the Gill et al.
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      study, the kappa statistics comparing NA with surgical diagnostic arthroscopy (standard bore size arthroscope) were very high, indicating no significant difference between the 2 modalities.
      In 1-way sensitivity analysis, MRI has always been more sensitive in medial versus lateral pathology.
      • Oei E.H.G.
      • Nikken J.J.
      • Verstijnen A.C.M.
      • et al.
      MR imaging of the menisci and cruciate ligaments: A systematic review.
      Thus, the overall positive finding threshold (TP + FP) for preferring MRI to NA is higher with medial versus lateral pathology (Tables 7 and 8). The lateral meniscus presents challenges based on the oblique orientation of the posterior horn with its sloping upward course at its attachment and small radial curvature. This makes tears of the posterior horn and tears involving less than one-third of the lateral meniscus difficult to identify on MRI.
      • De Smet A.A.
      • Mukherjee R.
      Clinical, MRI, and arthroscopic findings associated with failure to diagnose a lateral meniscal tear on knee MRI.
      • De Smet A.A.
      • Tuite M.J.
      • Norris M.A.
      • et al.
      MR diagnosis of meniscal tears: Analysis of causes of errors.
      This lower sensitivity has also not improved, despite improvements in magnet technology.
      • Diermengian C.A.
      • Dines J.S.
      • Verance J.V.
      • et al.
      Use of a small-bore needle arthroscopy to diagnose intra-articular knee pathology: Comparison with magnetic resonance imaging.
      It was also independent of the duration of the tear.
      • De Smet A.A.
      • Mukherjee R.
      Clinical, MRI, and arthroscopic findings associated with failure to diagnose a lateral meniscal tear on knee MRI.
      Based on inconclusive data presented from MRI, the vast majority of these tears tend to be ultimately be treated surgically.
      • De Smet A.A.
      • Tuite M.J.
      • Norris M.A.
      • et al.
      MR diagnosis of meniscal tears: Analysis of causes of errors.
      In these cases, it is likely that the initial use of NA (vs MRI) would have resulted in a more timely treatment of the tear, perhaps with less patient pain over time.
      From clinical practice, health policy, and patient satisfaction standpoints, NA may present advantages. NA is a diagnostic procedure that can be performed with the patient awake in a physician's office setting. A diagnosis can then be made by the clinician at that point, with 1 encounter establishing definitive diagnosis and treatment.
      Further, considering there can be a significant number of patients who are missed with MRI (i.e., FN findings) for the lateral meniscus pathology,
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      • Crawford R.
      • Walley G.
      • Bridgman S.
      • et al.
      Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: A systematic review.
      inappropriate care may be delivered. Additionally, based on the relatively high incidence of FP findings in medial meniscus pathology, there is the potential for unnecessary surgical treatment. There has been a push recently by policy makers and the medical community to ensure appropriate care is being delivered in all care settings, including emphasizing individual patient needs as the top priority.
      • Morden N.E.
      • Colla C.H.
      • Sequist T.D.
      • et al.
      Choosing wisely—The politics and economics of labeling low-value services.
      Thus, NA may be an alternative for delivering more appropriate care.
      The current analysis differs from a prior analysis that focused on Medicare costs only and was examined over the acute phase of care.
      • Voigt J.D.
      • Mosier M.
      • Huber B.
      Diagnostic needle arthroscopy and the economics of improved diagnostic accuracy: A cost analysis.
      This analysis includes private pay reimbursement and outcomes (KOOS4) and examines a patient over a 2-year period. This study also adds further clarity to the effect of NA on private insurers, where the majority of this type of condition is evaluated and treated.

      Limitations

      Indirect costs were not factored into this analysis. These costs include time absent from work, loss of productivity (owing to pain), out-of-pocket expenses related to transportation, travel time, assistive devices, and time spent on follow-up.
      • Hermans J.
      • Koopmanshcap M.A.
      • Bierma-Zeinstra S.M.A.
      • et al.
      Productivity costs and medical costs among working patients with knee osteoarthritis.
      • Marsh J.D.
      • Birmingham T.B.
      • Giffin J.R.
      • et al.
      Cost-effectiveness analysis of arthroscopic surgery compared with non-operative management for osteoarthritis of the knee.
      MRI results that were obtained from the literature were derived from academic medical centers where more advanced MRI technology (i.e., higher resolution of intra-articular disease) is available and generally where more experienced musculoskeletal radiologists reside.
      • Ben-Galim P.
      • Steinberg E.L.
      • Amir H.
      • et al.
      Accuracy of magnetic resonance imaging of the knee and unjustified surgery.
      MRI results from community practices have demonstrated lower accuracy.

      Viscosupplementation of the knee. Aetna policy #0179. Next review: February 8, 2018.

      KOOS4 was used as a proxy for outcome. This was a global score using 4 of the 5 subscale scores for patient with meniscal tears and osteoarthritis (pain, other symptoms, function in sports and recreation, and knee quality of life). The KOOS4 data were derived from a randomized controlled trial recently completed in middle-age patients (which was the population for this cost-effectiveness evaluation).
      • Kise N.J.
      • Risberg M.A.
      • Stennsrud S.
      • et al.
      Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: Randomised controlled trial with two year follow-up.
      It was assumed that all patients in the analysis would be willing to undergo NA in the office. This may not be the case, and there may crossover to MRI assessment owing to its noninvasive nature. This crossover was not accounted for in the analysis.
      It was assumed that symptomatic patients with TP and FP (with diagnosed pathology—either MRI or NA) were treated arthroscopically for a meniscectomy. This was based on an evidence-based review of meniscal tears after surgery with short-term satisfactory results occurring in approximately 90% of patients.
      • Mordecai S.C.
      • Al-Hadithy N.
      • Ware H.E.
      • et al.
      Treatment of meniscal tears: An evidence based approach.
      In other words, there is a high likelihood that patients will benefit from a surgical intervention. Additionally, with respect to FP MRI findings and our assumption that FP went on to surgery, Medicare CPT historical use data for the years 2000 to 2015 have shown a consistency of use for codes 29870 (diagnostic knee arthroscopy) and CPT 29880 plus 29881. CPT codes 29880/29881 have made up 73% to 75% of all surgical knee arthroscopies over this time frame.

      Centers for Medicare & Medicaid Services. Part B National Summary Data File (Previously known as BESS). https://www.cms.gov/Research-Statistics-Data-and-Systems/Downloadable-Public-Use-Files/Part-B-National-Summary-Data-File/Overview.html. Accessed August 7, 2018.

      CPT 29870 has also made up 1.2% to 1.3% of the 29880/29881 total. Since FPs in MRI are in the 10% to 15% range, the historical use of CPT 29870 should be much higher. It is therefore the assumption that FP MRI results are being treated surgically in everyday practice.
      The negative predictive value of MRI and NA has been shown to be quite high in meniscal tears,
      • Gill T.J.
      • Safran M.
      • Mandelbaum B.
      • et al.
      A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy.
      • Schurz M.
      • Erdoes J.T.
      • Petras N.
      • et al.
      The value of clinical examination and MRI versus intraoperative findings in the diagnosis of meniscal tears.
      and unless the patient had clinical symptoms indicative of a meniscal tear (along with a negative MRI and NA), follow-on arthroscopy was not performed. Since this occurs infrequently, surgery was not accounted for in TN findings.
      It was assumed patients were treated conservatively at first based on an FN finding. This was based on the standards of care for treating pain.
      • Jones B.Q.
      • Covey C.J.
      • Sineath M.H.
      Nonsurgical management of knee pain in adults.
      • Palmer T.
      • Toombs J.D.
      Managing joint pain in primary care.
      • Logerstedt D.S.
      • Schalzitti D.A.
      • Bennell K.L.
      • et al.
      Knee pain and mobility impairments: Meniscal and articular cartilage lesions. Revision 2018.
      Ultimately if the patient outcome did not improve, that patient underwent a surgical arthroscopic procedure.
      The use of MRI in patients with suspected bony edema (and with joint effusion) may be the more appropriate diagnostic modality versus NA because a differential diagnosis can be obtained. In patients with acute trauma with joint effusion, MRI can provide additional diagnostic capabilities regarding the condition of subchondral bone and alternative treatment(s).
      • Roemer F.W.
      • Frobell R.
      • Hunter D.J.
      • et al.
      MRI-detected subchondral one marrow signal alterations of the knee joint: Terminology, imaging appearance, relevance and radiological differential diagnosis.
      This was not evaluated in this analysis and is a limitation of the data evaluated.
      Last, the cost analysis covers 2 years only. Therefore, the findings of cost savings should be restricted to this time frame.

      Conclusions

      Based on the reported MRI incidence of FPs with the medial meniscus and FNs with the lateral meniscus based on assumed standards of care, more costly care is provided when using MRI compared with NA. Outcomes were similar with NA compared with MRI.

      Appendix

      Appendix Table 1Variables and Distributions Used in the Markov Model for Medicare
      Variables Used in the Model: Medial Meniscus Assessment/Treatment
      NameDescriptionFormulaValueLowHighComment
      Anesthesia_outpatient_meniscectomyCPT 01400: anesthesia for a 30-minute arthroscopic meniscectomy hospital outpatient setting$132$132$0$132Base units = 4; 1 unit each for 15 minutes of patient being under; total of 6 units. CMS 2017 CF = $22.05. Therefore, 6 units × $22.05 = $132.30
      APC_arthroscopic_meniscectomyAPC 5113: facility payment for surgical meniscectomy$2,425$2,425$0$2,425APC 5113: for use with CPT 29881. Medicare 2017 fee schedule.
      Corticosteroid_injectionCPT 20610: arthrocentesis and/or corticosteroid injection$62$62$0$62Medicare 2017 national average payment amount for arthrocentesis and/or corticosteroid injection.
      Cost_DVTCost to treat a DVT over a 12-month period$16,322$16,322$0$0Source: Spyropoulos AC, Lin J. Direct medical costs of VTE and subsequent hospital readmission rates: An administrative claims analysis form 30 managed care organizations. J Manag Care Pharma 2007;13:475-486. Costs inflated using medical CPT from 2007 to 2017.
      Cost_orthopedic_readmit_compCost orthopedic readmit owing to comp: DRG 565$6,623$6,623$0$12,000Medicare 2017 national average payment for DRG 565: OTHER MUSCULOSKELETAL SYS & CONNECTIVE TISSUE DIAGNOSES W CC
      Cost_PECost to treat a PE over a 12-month period$25,144$25,144$0$40,000Source: Spyropoulos AC, et al. (2007). Costs inflated using medical CPT from 2007 to 2017.
      Cost_VTECost to treat a VTE over a 12-month periodCost_complication_VTE$25,730$0$40,000Source: Lin J, Lingohr-Smith M, Kowng WJ. Incremental health care resource utilization and economic burden of venous thromboembolism recurrence from a US payer perspective. Jrl Manag Care Pharm 2014;20:174-186.
      Cost_Wound_comp_arthroscopic_lavage_drainageCPT 29871: arthroscopic lavage and drainage for infection + APC 5113$2,956$2,956$0$5,000Medicare 2017 national average payment rate for arthroscopic lavage and drainage: infection plus APC 5113 at $2,425.
      CPT_arthroscopic_meniscectomyCPT 29881: partial meniscectomy, medial or lateral$558$558$0$1,000Medicare 2017 national average payment amount for a meniscectomy of the knee: medial or lateral; facility setting.
      CPT_diagnostic_arthroscopy_knee_MedicareCPT 29870: diagnostic knee arthroscopy physician office, Medicare$598$598$0$1,500Medicare 2017 national average payment amount for a diagnostic knee arthroscopy: physician office setting.
      CPT_diagnostic_arthroscopy_knee_PPCPT 29870: diagnostic knee arthroscopy physician office, private pay$958$958$0$3,000Average private payer rates for NA obtained from explanation of benefits for various payers, including Blue Cross Blue Shield, Aetna, United, CIGNA, Harvard Pilgrim Health Plan. Mean ± SD = $958 ± $317.
      CPT_Evaluation_Mgmt_ExistingCPT code for a follow-up evaluation and management on an existing patient$109$109$0$200Medicare 2017 national average payment amount for a 30-minute physical examination: existing patient.
      CPT_Evaluation_Mgmt_existing_injectionCost E&M for injection corticosteroid: CPT 99212$44$44$0$100Medicare 2017 national average payment rate: CPT 99212.
      CPT_Evaluation_Mgmt_NewCPT code for evaluation and management: patient history and examination$166$166$0$300Medicare 2017 national average payment amount for a 30-minute physical examination: new patient.
      CPT_MRI_knee_MedicareCPT 73721: MRI knee without contrast, Medicare$240$240$0$1,500Medicare 2017 national average payment amount for an MRI of the knee without contrast.
      CPT_MRI_Knee_PPCPT 73721: MRI knee without contrast, private pay$1,628$1,628$0$3,000Cooper Z, Craig SV, Gaynor M, Van Reenen J. The price ain’t right? Hospital prices and health spending on the privately insured. Working paper 21815. National Bureau of Economic Research. Published December 2015. Revised May 2018. The 2011 reimbursement rates are inflated to 2017.
      CPT_Xray_kneeCPT 73564 x-ray knee: 4 views$40$40$0$80Medicare 2017 national average payment amount for x-rays of the knee: 4 views.
      KOOS4_baseline_scoreKOOS4_baseline56.95085Source: Kise NJ, Risberg MA, Stensrud S, Ranstam J, Engebretsen L, Roos EM. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up. BMJ 2016;354:i3740.
      KOOS4_one_year_exerciseKOOS4_excercise_one_year82.53090Source: Kise NJ, et al. (2016).
      KOOS4_one_year_meniscectomyKOOS4_meniscectomy_one_year86.93095Source: Kise NJ, et al. (2016).
      KOOS4_two_year_exerciseKOOS4_exercise_two_years88.2095Source: Kise NJ, et al. (2016).
      KOOS4_two_year_meniscectomyKOOS4_meniscectomy_two_years87.4095Source: Kise NJ, et al. (2016).
      MRI_positivesMRI positive findings out of all findings (positive + negative)Positive_findings_MRI55%0%99%Crawford R, Walley G, Bridgman S, Mafulli N. Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: A systematic review. Br Med Bull 2007;84:5-23.
      NA_positivesNeedle arthroscopy positive findings out of all NA findings (positive + negative)Positive_findings_NA43%0%99%Based on VisionScope NA findings. Data on file.
      Physical_therapy_cost_weekCost physical therapy per week$660$660$0$15,000CPT 97110 pays at $33 per 15-minute session. Assume 4 sessions per day; 5 days per week. Therefore, $33 × 4 × 5 = $660 per week.
      Physical_therapy_initial_evaluationCPT 97162: initial evaluation for physical therapy$83$83$0$150Medicare 2017 national average payment for CPT 97162: initial evaluation for physical therapy.
      Physical_therapy_kneePhysical therapy knee: assume 3-6 weeksPhysical_therapy_duration_post_surg4.509Assumed course of physical therapy based on coverage determinations of Medicare and private payers.
      Probability_comp_DVTProbability DVT meniscal surgical arthroscopic procedure0.12%0.12%0%1%Source: Jameson SS, Dowen D, James P, Serrano-Pedraza I, Reed MR, Deehan DJ. The burden of arthroscopy of the knee: a contemporary analysis of data from the English NHS. J Bone Joint Surg Br 2011;93:1327-1333.
      Probability_comp_PEProbability PE meniscal surgical arthroscopic procedure0.08%0.08%0%0.2%Source: Jameson SS, et al. (2011).
      Probability_comp_readmitProbability readmit owing to meniscal surgical arthroscopic procedure0.45%0.45%0%1%Source: Jameson SS, et al. (2011).
      Probability_comp_VTEProbability VTE meniscal arthroscopic surgical procedure0.19%0.19%0%0.5%Source: Jameson SS, et al. (2011).
      Probability_comp_woundProbability wound complication meniscal arthroscopic surgical procedure0.11%0.11%0%0.5%Source: Jameson SS, et al. (2011).
      Probability_complicationProbability complication post knee surgeryProbability_complication_knee_arthroscopy1%0%2%Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month time frame. Derived from the medical literature and inflated to 2017.
      Probability_pain_meds_successProbability corticosteroid injections relived pain symptoms50%50%0%90%Estimated.
      Probability_rehab_post_med_failureProbability exercise rehabilitation post medication failure85%85%0%95%Source: Cavanaugh JT, Killian SE. Rehabilitation following meniscal repair. Curr Rev Musculoskelet Med 2012;5:46-58.
      Probability_rehab_successProbability rehab success post meniscectomyProbability_meniscal_repair_success80%0%90%Source: Cavanaugh JT, et al. (2012)
      TN_MRITrue_negatives_MRI90%0%95%Crawford R, et al. (2007).
      TN_NATrue_Negatives_NA86%0%99%Based on VisionScope NA findings. Data on file.
      TP_MRITrue_positives_MRI83%0%95%Crawford R, et al. (2007).
      TP_NATrue_positives_NA97%0%99%Based on VisionScope NA findings. Data on file.
      Weighted_average_complication_costWeighted_average_cost_complication$12,804$0$20,000Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month time frame. Derived from the medical literature and inflated to 2017.
      Distributions Used in the Model
      DescriptionTypeParametersEVComment
      Physical therapy in weeks after arthroscopic meniscal surgeryUniformSubtype: 2, low: 3, high: 64.5Assumed course of physical therapy based on coverage determinations of Medicare and private payers.
      Cost of treating a VTE over a 12-month period, MedicareNormalMean: 25730; SD: 40,250$25,730Source: Lin J, et al. (2014).
      Weighted average cost of a complication post arthroscopyNormalMean: 12804; SD: 10,000$12,804Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month time frame. Derived from the medical literature and inflated to 2017.
      Percentage of positive findings on MRI vs total findingsUniformSubtype: 2; low: 0.4; high: 0.755%Assumed positive findings for medial meniscus pathology for MRI.
      Percentage of TNs of all negative findings MRI (TN + FN)UniformSubtype: 2; low: 0.85; high: 0.9590%Assumed negative findings for medial meniscus pathology for MRI.
      KOOS4 at 2-year exercise groupTriangularMin: 81.1; likeliest: 85; max: 98.588.2Source: Kise NJ, et al. (2016).
      Probability of meniscus repair success post rehabUniformSubtype: 2; low: 0.7; high: 0.980.0%Source: Cavanaugh JT, et al. (2012).
      Percentage of positive findings of all findings NA (TP + FP)UniformSubtype: 2; low: 0.4; high: 0.4542.5%Based on VisionScope NA findings. Data on file.
      Probability knee complicationTriangularMin: 0.001; likeliest: 0.0095; max: 0.021.02%Probability of a complication based on all complications summed up: 0.95%
      Percentage of TN NA of all negatives (TN + FN)TriangularMin: 0.725; likeliest: 0.882; max: 0.96785.8%Based on VisionScope NA findings. Data on file.
      KOOS4 at 1-year exerciseTriangularMin: 74.9; likeliest: 79.5; max: 93.282.53Source: Kise NJ, et al. (2016).
      Percentage of TPs of all positives (TP + FP)TriangularMin: 0.922; likeliest: 0.986; max: 196.9%Based on VisionScope NA findings. Data on file.
      Percentage of TPs of all positive MRI findings (TP + FP)UniformSubtype: 2; low: 0.8; high: 0.8582.5%Crawford R, et al. (2007).
      KOOS4 at 2-year meniscectomyTriangularMin: 80.4; likeliest: 84.1; max: 97.787.4Source: Kise NJ, et al. (2016).
      KOOS4 at 1-year meniscectomyTriangularMin: 79.9; likeliest: 83.7; max: 97.286.93Source: Kise NJ, et al. (2016).
      KOOS4 baseline score meniscus damageNormalMean: 56.95; SD: 16.3756.95Source: Kise NJ, et al. (2016). Combined mean from exercise and meniscectomy groups: N = 70 both groups; mean ± SD exercise: 54.3 ± 18.2 and meniscectomy: 59.6 ± 13.8.
      APT, Ambulatory Payment Classification; CPT, Current Procedure Terminology; DRG, Diagnosis Related Group; DVT, deep vein thrombosis; E&M, evaluation and management; EV, expected value; FN, false negative; FP, false positive; KOOS, knee injury and osteoarthritis outcome score; MRI, magnetic resonance imaging; NA, needle arthroscopy; PE, pulmonary embolism; SD, standard deviation; TN, true negative; TP, true positive; VTE, venous thromboembolism.
      Appendix Table 2Medicare Costs Over 2-Year Time Frame by Diagnostic Modality and Subsequent Treatment
      True Positive, Needle Arthroscopy, Medical Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectTotal Effect
      0Surgical treatment100.003,9193,9193,91956.9556.9556.95
      0Rehabilitation0.0003,9193,9190.0056.9556.95
      0Pain meds/injections0.0003,9193,9190.0056.9556.95
      0Success0.0003,9193,9190.0056.9556.95
      0Complication0.0003,9193,9190.0056.9556.95
      1Surgical treatment0.0004,1328,0510.0086.63143.58
      1Rehabilitation98.984,0024,1328,05186.0586.63143.58
      1Pain meds/injections0.0004,1328,0510.0086.63143.58
      1Success0.0004,1328,0510.0086.63143.58
      1Complication1.021304,1328,0510.5886.63143.58
      2Surgical treatment0.000628,1130.0018.35161.93
      2Rehabilitation1.0241628,1130.8918.35161.93
      2Pain meds/injections19.81021628,11317.4618.35161.93
      2Success79.190628,1130.0018.35161.93
      2Complication0.000628,1130.0018.35161.93
      False Positive, Needle Arthroscopy, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectTotal Effect
      0Surgical treatment100.003,9193,9193,91956.9556.9556.95
      0Rehabilitation0.0003,9193,9190.0056.9556.95
      0Pain meds/injections0.0003,9193,9190.0056.9556.95
      0Success0.0003,9193,9190.0056.9556.95
      0Complication0.0003,9193,9190.0056.9556.95
      1Surgical treatment0.0004,1328,0510.0086.63143.58
      1Rehabilitation98.984,0024,1328,05186.0586.63143.58
      1Pain meds/injections0.0004,1328,0510.0086.63143.58
      1Success0.0004,1328,0510.0086.63143.58
      1Complication1.021304,1328,0510.5886.63143.58
      2Surgical treatment0.000628,1130.0018.35161.93
      2Rehabilitation1.0241628,1130.8918.35161.93
      2Pain meds/injections19.81021628,11317.4618.35161.93
      2Success79.190628,1130.0018.35161.93
      2Complication0.000628,1130.0018.35161.93
      True Negative, Needle Arthroscopy, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectTotal Effect
      0Negative finding100.0080480480456.9556.9556.95
      1Negative finding100.000080482.5382.53139.48
      2Negative finding100.000080488.2088.20227.68
      False Negative, Needle Arthroscopy, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectiveStage EffectiveTotal Effective
      0Rehabilitation100.001,5471,5471,54756.9556.9556.95
      0Sodium hyaluronate injections0.0001,5471,5470.0056.9556.95
      0Surgical treatment0.0001,5471,5470.0056.9556.95
      0Success0.0001,5471,5470.0056.9556.95
      0Complication0.0001,5471,5470.0056.9556.95
      1Rehabilitation0.0001571,7040.0016.5173.46
      1Sodium hyaluronate injections20.001571571,70416.5116.5173.46
      1Surgical treatment0.0001571,7040.0016.5173.46
      1Success80.0001571,7040.0016.5173.46
      1Complication0.0001571,7040.0016.5173.46
      2Rehabilitation0.0001521,8550.000.0073.46
      2Sodium hyaluronate injections0.0001521,8550.000.0073.46
      2Surgical treatment4.871521521,8550.000.0073.46
      2Success95.1301521,8550.000.0073.46
      2Complication0.0001521,8550.000.0073.46
      True Positive, Magnetic Resonance Imaging, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectiveTotal Effective
      0Surgical treatment100.003,7803,7803,78056.9556.9556.95
      0Rehabilitation0.0003,7803,7800.0056.9556.95
      0Pain meds/injections0.0003,7803,7800.0056.9556.95
      0Success0.0003,7803,7800.0056.9556.95
      0Complication0.0003,7803,7800.0056.9556.95
      1Surgical treatment0.0004,1327,9120.0086.63143.58
      1Rehabilitation98.984,0024,1327,91286.0586.63143.58
      1Pain meds/injections0.0004,1327,9120.0086.63143.58
      1Success0.0004,1327,9120.0086.63143.58
      1Complication1.021304,1327,9120.5886.63143.58
      2Surgical treatment0.000627,9740.0018.35161.93
      2Rehabilitation1.0241627,9740.8918.35161.93
      2Pain meds/injections19.81021627,97417.4618.35161.93
      2Success79.190627,9740.0018.35161.93
      2Complication0.000627,9740.0018.35161.93
      False Positive, Magnetic Resonance Imaging, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectiveTotal Effect
      0Surgical treatment100.003,7803,7803,78056.9556.9556.95
      0Rehabilitation0.0003,7803,7800.0056.9556.95
      0Pain meds/injections0.0003,7803,7800.0056.9556.95
      0Success0.0003,7803,7800.0056.9556.95
      0Complication0.0003,7803,7800.0056.9556.95
      1Surgical treatment0.0004,1327,9120.0086.63143.58
      1Rehabilitation98.984,0024,1327,91286.0586.63143.58
      1Pain meds/injections0.0004,1327,9120.0086.63143.58
      1Success0.0004,1327,9120.0086.63143.58
      1Complication1.021304,1327,9120.5886.63143.58
      2Surgical treatment0.000627,9740.0018.35161.93
      2Rehabilitation1.0241627,9740.8918.35161.93
      2Pain meds/injections19.81021627,97417.4618.35161.93
      2Success79.190627,9740.0018.35161.93
      2Complication0.000627,9740.0018.35161.93
      True Negative, Magnetic Resonance Imaging, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectStage EffectTotal Effect
      0Negative100.0077477477456.9556.9556.95
      1Negative100.000077482.5382.53139.48
      2Negative100.000077488.2088.20227.68
      False Negative, Magnetic Resonance Imaging, Medial Meniscus
      StageStateProbability, %State Cost, $Stage Cost, $Total Cost, $State EffectiveStage EffectiveTotal Effective
      0Rehabilitation100.001,4081,4081,40856.9556.9556.95
      0Sodium hyaluronate injections0.0001,4081,4080.0056.9556.95
      0Surgical treatment0.0001,4081,4080.0056.9556.95
      0Success0.0001,4081,4080.0056.9556.95
      0Complication0.0001,4081,4080.0056.9556.95
      1Rehabilitation0.0001571,5650.0016.5173.46
      1Sodium hyaluronate injections20.001571571,56516.5116.5173.46
      1Surgical treatment0.0001571,5650.0016.5173.46
      1Success80.0001571,5650.0016.5173.46
      1Complication0.0001571,5650.0016.5173.46
      2Rehabilitation0.0001521,7160.000.0073.46
      2Sodium hyaluronate injections0.0001521,7160.000.0073.46
      2Surgical treatment4.871521521,7160.000.0073.46
      2Success95.1301521,7160.000.0073.46
      2Complication0.0001521,7160.000.0073.46
      Appendix Table 3Variables and Distributions Used in the Private Pay Model
      Private Pay Variables
      NameDescriptionFormulaValueLowHighComment
      Anesthesia_outpatient_meniscectomyCPT 01400: anesthesia for a 30-minute arthroscopic meniscectomy, hospital outpatient setting$180$180$0$250Base units = 4; 1 unit each of 15 minutes of patient being under; total of 6 units. CMS 2017 CF = $22.05. Therefore, 6 units × $22.05 = $132.30. Assuming a 30% markup for private pay over Medicare = 132 × 1.3 = 180.
      APC_arthroscopic_meniscectomyAPC 5113: facility payment for surgical meniscectomy$3,153$3,153$0$4,000APC 5113: for use with CPT 29881. Assume 30% markup for private pay: $2425 × 1.3 = 3153.
      Cost_HA_injectionUse of Medicare J7323 Euflexxa per dose = $155$155$155$0$500Derived from Medicare payment rate for J7323 at $155.
      CPT_arthroscopic_meniscectomyCPT 29881: partial meniscectomy, medial or lateral$725$725$0$1,000Medicare 2017 national average payment amount for a meniscectomy of the knee: medial or lateral; facility setting. Assume 30% markup of private pay over Medicare: $558 × 1.3 = $725.
      CPT_diagnostic_arthroscopy_kneeCPT 29870: diagnostic knee arthroscopy, physician officeNA_knee$958$0$3,000Private payer national average payment amount for a diagnostic knee arthroscopy: physician office setting. Data on file VisionScope.
      CPT_Evaluation_Mgmt_ExistingCPT code for a follow-up evaluation and management on an existing patient$142$142$0$180Medicare 2017 national average payment amount for a 30-minute physical examination: existing patient. Assume 30% markup of private pay over Medicare: $109 × 1.3 = $142.
      CPT_Evaluation_Mgmt_existing_injectionCost E&M for injection corticosteroid: CPT 99212$57$57$0$100Medicare 2017 national average payment rate: CPT 99212. Assume 30% markup of private pay over Medicare: $44 × 1.3 = $57.
      CPT_Evaluation_Mgmt_NewCPT code for evaluation and management: patient history and examination$216$216$0$300Medicare 2017 national average payment amount for a 30-minute physical examination: new patient. Assume 30% markup of private pay over Medicare: $166 × 1.3 = $216.
      CPT_MRI_kneeCPT 73721: MRI knee without contrastMRI_knee$1,628$0$3,000Private pay 2017 national average payment amount for an MRI of the knee without contrast: hospital setting. Truveen data.
      CPT_Xray_kneeCPT 73564 x-ray knee: 4 views$52$52$0$100Medicare 2017 national average payment amount for x-rays of the knee: 4 views. Assume 30% markup of private pay over Medicare rate: $40 × 1.3 = $52.
      HA_injectionCPT 20610: arthrocentesis and/or injection$81$81$0$160Medicare 2017 national average payment amount for arthrocentesis and/or corticosteroid injection. Assume 30% markup of private pay over Medicare: 62 × 1.3 = 81.
      KOOS4_baseline_scoreKOOS4_baseline56.950.0080.00Source: Kise NJ, Risberg MA, Stensrud S, Ranstam J, Engebretsen L, Roos EM. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up. BMJ 2016;354:i3740.
      KOOS4_one_year_exerciseKOOS4_excercise_one_year82.530.0090.00Source: Kise NJ, et al. (2016).
      KOOS4_one_year_meniscectomyKOOS4_meniscectomy_one_year86.930.0095.00Source: Kise NJ, et al. (2016).
      KOOS4_two_year_exerciseKOOS4_exercise_two_years88.200.0095.00Source: Kise NJ, et al. (2016).
      KOOS4_two_year_meniscectomyKOOS4_meniscectomy_two_years87.400.0095.00Source: Kise NJ, et al. (2016).
      MRI_positivesMRI positive findings out of all findings (positive + negative)Positive_findings_MRI55.0%0.0%99.0%Crawford R, Walley G, Bridgman S, Mafulli N. Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: A systematic review. Br Med Bull 2007;84:5-23.
      NA_positivesNeedle arthroscopy positive findings out of all NA findings (positive + negative)Positive_findings_NA42.5%0.0%99.0%Based on VisionScope NA findings. Source: Gill TJ, Safran M, Mandelbaum B, Huber B, Gambardella R, Xerogeanes J. A prospective, blinded, multicenter clinical trial to compare the efficacy, accuracy, and safety of in-office diagnostic arthroscopy with magnetic resonance imaging and surgical arthroscopy. Arthroscopy 2018;34:2429-2435.
      Physical_therapy_cost_weekCost of physical therapy per week858$858$0$1,500CPT 97110 pays at $33 per 15-minute session. Assume 4 sessions per day; 5 days per week. Therefore, $33 × 4 × 5 = $660 per week. Assume 30% markup of private pay over Medicare: $660 × 1.3 = $858.
      Physical_therapy_initial_evaluationCPT 97162: initial evaluation for physical therapy108$108$0$200Medicare 2017 national average payment for CPT 97162: initial evaluation for physical therapy. Assume 30% markup of private payer over Medicare: $83 × 1.3 = $108.
      Probability_complicationProbability complication post knee surgeryProbability_complication_knee_arthroscopy1.0%0.0%10.0%Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month timeframe. Derived from the medical literature and inflated to 2017.
      Probability_HA_successProbability that HA is successful in relieving painHA_effectiveness75.7%0.0%90.0%Source: Concoff A, Sancheti P, Niazi F, Shaw P, Rosen J. The efficacy of multiple versus single hyaluronic acid injections: A systematic review and meta-analysis. BMC Musculoskel Disord 2017;18(1):542.
      Probability_pain_meds_successProbability corticosteroid injections relieved pain symptoms0.550.0%0.0%80.0%Estimated
      Probability_rehab_post_med_failureProbability exercise rehabilitation post medication failure0.8585.0%0.0%95.0%Source: Cavanaugh JT, Killian SE. Rehabilitation following meniscal repair. Curr Rev Musculoskelet Med 2012;5:46-58.
      Probability_rehab_successProbability rehab success post meniscectomyProbability_meniscal_repair_success80.0%0.0%90.0%Source: Cavanaugh JT, et al. (2012).
      TN_MRITrue_negatives_MRI90.0%0.0%95.0%Crawford R, et al. (2007).
      TN_NATrue_Negatives_NA85.8%0.0%99.0%Based on VisionScope NA findings. Source: Gill TJ, et al. (2018).
      TP_MRITrue_positives_MRI82.5%0.0%90.0%Crawford R, et al. (2007).
      TP_NATrue_positives_NA96.9%0.0%99.0%Based on VisionScope NA findings. Source: Gill TJ, et al. (2018).
      Weighted_average_complication_costWeighted_average_cost_complication$12,804$0$20,000Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month time frame. Derived from the medical literature and inflated to 2017.
      Private Pay Distributions
      NameDescriptionTypeParametersEVComment
      Physical_therapy_duration_post_surgPhysical therapy in weeks post arthroscopic meniscal surgeryUniformSubtype: 2; low: 3; high: 64.5Assumed course of physical therapy based on coverage determinations of Medicare and private payers.
      Cost_complication_VTECost of treating a VTE over a 12-month period: MedicareNormalMean: 25,730; SD: 40,250$25,730Source: Lin J, Lingohr-Smith M, Kowng WJ. Incremental health care resource utilization and economic burden of venous thromboembolism recurrence from a US payer perspective. Jrl Manag Care Pharm 2014;20:174-186.
      Weighted_average_cost_complicationWeighted average cost of a complication post arthroscopyNormalMean: 12,804, standard deviation: 10000$12,804Weighted average cost of DVT, PE, VTE, readmit, wound complication based on the probabilities of occurrence and over a 12-month time frame. Derived from the medical literature and inflated to 2017.
      Positive_findings_MRIPercentage of positive findings on MRI vs total findingsUniformSubtype: 2, low: 0.4, high: 0.755%Assumed positive findings for medial meniscus pathology for MRI.
      True_negatives_MRIPercentage of TNs of all negative findings MRI (TN + FN)UniformSubtype: 2, low: 0.85, high: 0.9590%Assumed negative findings for medial meniscus pathology for MRI.
      KOOS4_exercise_two_yearsKOOS4 at 2-year exercise groupTriangularMin: 81.1, likeliest: 85, max: 98.588.2Source: Kise NJ, et al. (2016).
      HA_effectivenessHA effectiveness in relieving painTriangularMin: 0.53, likeliest: 0.76, max: 0.9875.7%Source: Concoff A, et al. (2017).
      Probability_meniscal_repair_successProbability of meniscus repair success post rehabUniformSubtype: 2, low: 0.7, high: 0.980.0%Source: Cavanaugh JT, et al. (2012.
      NA_kneePrivate payer amount NA POSNormalMean: 958, standard deviation: 317$958Data on file VisionScope; 400 plus data points from private insurers.
      Positive_findings_NAPercentage of positive findings of all findings NA (TP + FP)UniformSubtype: 2, low: 0.4, high: 0.4542.50%Source: Gill TJ, et al. (2018).
      Probability_complication_knee_arthroscopyProbability of knee complicationTriangularMin: 0.001, likeliest: 0.0095, max: 0.021.02%Probability of a complication based on all complications summed up: 0.95%.
      True_Negatives_NAPercentage of TNs NA of all negatives (TN + FN)TriangularMin: 0.725, likeliest: 0.882, max: 0.96785.80%Source: Gill TJ, et al. (2018).
      KOOS4_excercise_one_yearKOOS4 at 1-year exerciseTriangularMin: 74.9, likeliest: 79.5, max: 93.282.533Source: Kise NJ, et al. (2016).
      True_positives_NAPercentage of TPs of all positives (TP + FP)TriangularMin: 0.922, likeliest: 0.986, max: 196.93%Source: Gill TJ, et al. (2018).
      True_positives_MRIPercentage of TPs of all positive MRI findings (TP + FP)UniformSubtype: 2, low: 0.8, high: 0.8582.50%Source: Crawford R, et al. (2007).
      KOOS4_meniscectomy_two_yearsKOOS4 at 2-year meniscectomyTriangularMin: 80.4, likeliest: 84.1, max: 97.787.4Source: Kise NJ, et al. (2016).
      KOOS4_meniscectomy_one_yearKOOS4 at 1-year meniscectomyTriangularMin: 79.9, likeliest: 83.7, max: 97.286.933Source: Kise NJ, et al. (2016).
      KOOS4_baselineKOOS4 baseline score meniscus damageNormalMean: 56.95, standard deviation: 16.3756.95Source: Kise NJ, et al. (2016). Combined mean from exercise and meniscectomy groups: N = 70 both groups. Mean ± SD exercise: 54.3 ± 18.2 and meniscectomy: 59.6 ± 13.8.
      MRI_kneePrivate payer rate MRI kneeNormalMean: 1628, standard deviation: 622$1,628Available from Truven Analytics.
      CPT, Current Procedural Terminology; DVT, deep vein thrombosis; E&M, evaluation and management; EV, expected value; HA, hyaluronic acid; FN, false negative; FP, false positive; KOOS, knee injury and osteoarthritis and outcome score; MRI, magnetic resonance imaging; NA, needle arthroscopy; PE, pulmonary embolism; POS, physician office setting; SD, standard deviation; TN, true negative; TP, true positive; VTE, venous thromboembolism.

      Supplementary Data

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