Did Changes in the IPO List Have an Impact on Health Disparities in TJA?

Three major events that occurred over the last 5 years have largely been responsible for driving joint replacement procedures to the outpatient setting:

  • The Centers for Medicare and Medicaid Services (CMS) removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) List for Medicare beneficiaries as of calendar year 2018.
  • As of calendar year 2020, total hip arthroplasty (THA) joined TKA and was also removed from the IPO List by CMS.
  • In the first quarter of 2020, elective surgeries such as TKA and THA were first paused for months due to the COVID-19 pandemic and then moved to outpatient facilities – either freestanding or based at a hospital – to allow elective procedures to continue while reserving scarce hospital resources for COVID-19 patients.

Even before any of those major changes, racial and ethnic disparities in access to total joint arthroplasty care were a concern. At the recent 2022 Annual Meeting of the American Academy of Orthopaedic Surgeons, researchers from NYU Langone Health presented the findings from their study that investigated the impact these changes may have had on health disparities for different racial and ethnic groups.

Study Methods and Findings

From the NYU Langone Health electronic medical records database, the study authors identified all patients who underwent TKA (n=11,819) or THA (n=10,212) between 2015 and 2021. Patients were classified as outpatients if they were discharged the same day as or the day after surgery; all others were classified as inpatients. Outpatients were further classified by the time period during which their procedure was performed:

  • Period A: Before 2018 (ie, before TKA and THA were removed from the IPO list)
  • Period B: Between 2018 and 2020 (ie, after TKA was removed from the IPO list but before THA was removed)
  • Period C: After 2020 (ie, after both procedures had been removed from the IPO list and with the impact of the COVID pandemic)

The researchers then examined the percentage of outpatients within different racial and ethnic groups for each time period, as well as 90-day readmission rates.

The researchers found that Black and Hispanic patients were less commonly designated as outpatients than white patients. Black THA patients also had significantly higher rates of readmission than white patients between 2018 and 2020, before THA was removed from the IPO list. There were no significant differences in readmissions across races or ethnicities.

Study Implications

“The implications of regulatory changes can be wide-ranging and lag behind available data,” says Claudette M. Lajam, MD, senior author of the study and chief safety officer for the department. “Additional study is needed to ensure these broad changes to the Inpatient Only List are not restricting access to high-quality care.

“As surgeons, we’re making decisions every day that impact lives and we want to make certain our policies lead to the best possible outcomes for every patient.”


Bosco JA, Oeding JF, Grobaty LE, Lajam CM. Removal of Total Hip and Total Knee Arthroplasty from the Inpatient Only List: Impact on Health Disparities (Paper 272). Presented at the American Academy of Orthopaedic Surgeons’ 2022 Annual Meeting, March 22-26, 2022, Chicago, Illinois.

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