Medicaid Expansion Associated with a Rise in Demand for THA and TKA, Study Finds

    Demand for hip and knee arthroplasty surged shortly after states expanded Medicaid eligibility under the Affordable Care Act, suggesting a previously unmet need for joint replacement surgery among Americans who were newly qualified for Medicaid insurance.

    Researchers from Washington University School of Medicine in St. Louis, Missouri, used administrative data from a Medicaid managed care program to analyze the timing of primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) among adults age 18 to 64. The study included patients from 4 states that had expanded Medicaid eligibility in 2014 – Illinois, Ohio, Oregon, and Washington – and from 4 states that had not expanded Medicaid – Louisiana, Mississippi, Texas, and Wisconsin.

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    Times to joint replacement surgery were compared among 3 groups:

    • Medicaid-expansion patients, a relatively healthy group of adults without dependent children
    • Medicaid patients with Supplemental Security Income (SSI), a group of relatively unhealthy adults with disabilities
    • Patients receiving Temporary Assistance for Needy Families (TANF), who are parents of children with Medicaid insurance

    The analysis included a total of 4117 patients across the 3 groups.

    The researchers found that the median time to THA or TKA for newly enrolled Medicaid expansion beneficiaries was significantly shorter than for SSI patients and TANF patients: 7.5 months, 16.1 months, and 12.2 months, respectively. After adjusting for other factors, the time to THA or TKA was 70% shorter for Medicaid-expansion patients than for SSI patients. For TANF patients, the time to THA or TKA was 24% shorter than for SSI patients.

    Expansion of state Medicaid programs has led to dramatic increases in insurance coverage among Americans. In August, Medicaid expansion was approved by voters in Missouri, making it the 38th state to expand Medicaid coverage.

    As this study showed, Medicaid-expansion states have seen increases in certain elective but clinically indicated surgical procedures, including THA and TKA, which raises questions of whether pent-up demand will strain the capacity of the healthcare system or exceed the supply of orthopaedic surgeons willing to accept Medicaid insurance.

    “This need should be considered by surgeons, hospitals, and policymakers in ensuring access to care,” the study authors concluded. “Furthermore, consideration should be given to existing insurance-based disparities in access to orthopaedic care, as these may be exacerbated by an increased demand for THA and TKA from Medicaid expansion beneficiaries.”


    Dy CJ, Barker AR, Brown DS, et al. Unmet need for total joint arthroplasty in Medicaid beneficiaries after Affordable Care Act expansion. J Bone Joint Surg Am. 2020;102(17):1495-1500.