ACA Expansion Linked to HIGHER THA, TKA Volumes

As Medicaid coverage expanded under the Affordable Care Act (ACA), noticed the authors of a new study, so did the utilization of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Was there indeed a pent-up demand and therefore an unmet need for knee and hip repair?

The researchers, all from Washington University School of Medicine in St. Louis, Missouri, (WUSTL) examined whether patients with Medicaid expansion insurance would have surgery sooner than patients in traditional Medicaid populations.

Their study, “Unmet Need for Total Joint Arthroplasty in Medicaid Beneficiaries After Affordable Care Act Expansion,” appears in the September 2, 2020 edition of The Journal of Bone and Joint Surgery.

Study co-author, Christopher J. Dy, M.D., M.P.H., assistant professor in the Department of Orthopaedic Surgery at WUSTL, explained the genesis of the research to OTW: “Numerous studies, including some of the work from our own lab, has shown the difficulty that Medicaid patients have in accessing care. One of the goals of the ACA was to increase access to care.”

“Our prior work in the Journal of Arthroplasty has shown that Medicaid expansion (enabled by the ACA) significantly increases the utilization of two of the most common orthopaedic surgeries (THA, TKA). We wanted to investigate whether there was a pent-up demand for THA and TKA among those who gained insurance from Medicaid expansion, as this would help surgeons and policymakers plan for increased utilization of these life-improving surgeries.”

Looking at the years 2008-2015, the team pulled data from a Medicaid managed care company to assess the timing of primary THA and TKA in patients in four states with Medicaid expansion (Illinois, Ohio, Oregon, and Washington) and four states without Medicaid expansion (Louisiana, Mississippi, Texas, and Wisconsin). The three groups involved were: Medicaid expansion, Medicaid plans for Supplemental Security Income (SSI), or Temporary Assistance for Needy Families (TANF). Their primary outcome measure was the time period from enrollment until surgery.

Of the 4,117 patients in the study (adjusted for age, sex, social deprivation, surgeon supply and reimbursement, state-level Medicaid enrollment) the time from enrollment to THA and TKA was significantly shorter in the expansion group compared with the Temporary Assistance for Needy Families group and the Supplemental Security Income group. “Compared with the SSI group,” say the authors, “these coefficients are equivalent to a 70% shorter time to the surgical procedure in the expansion group and a 24% shorter time to the surgical procedure in the TANF group.”

Dr. Dy: “Patients with Medicaid expansion insurance plans had significantly shorter times from insurance enrollment to having their THA or TKA, compared to other types of Medicaid plans.”

“There is a pent-up demand for THA and TKA among those who are newly insured under the ACA. While we did not examine it directly, this finding likely applies to other areas of orthopaedics such as hand surgery, sports medicine, and spine surgery—these are all areas with cost-effective, life-changing interventions. Surgeons, health systems leaders, and policymakers should be prepared for the expected surge in demand for orthopaedic services after Medicaid expansion.”