Trends and Outcomes in Outpatient vs. Inpatient TJA

    With the number of outpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures increasing nationwide, Geoffrey Westrich, MD, and colleagues at Hospital for Special Surgery wanted to know: Are patients who go home the same day as surgery more likely to be readmitted with complications from surgery than those who spend 1 or more nights in the hospital?

    Using data from the PearlDiver Mariner Database, they found no significant difference in complication rates requiring a hospital readmission for patients who underwent outpatient THA, and only slightly higher odds of complications for outpatient TKA patients.

    The study has been published online ahead of print by The Journal of Arthroplasty.

    Limited Data on Outcomes

    “In recent years there has been increasing interest among surgeons and hospital systems in shifting joint replacement to outpatient centers safely and efficiently,” said Dr. Westrich, research director emeritus in the Adult Reconstruction and Joint Replacement Service at Hospital for Special Surgery. 

    RELATED: Which Medicare Patients Undergoing TKA Should Be Inpatients versus Outpatients?

    “However, there [have] been limited data on trends, comorbidities, and complications in patients discharged the same day they have surgery.”

    For their study, Dr. Westrich and colleagues identified nearly 1.8 million patients in the PearlDiver database who had undergone primary, elective THA or TKA between 2010 and 2017 (68.8% TKA, 31.2% THA). These patients were divided into groups based on which surgery they had and whether it was performed on an inpatient or outpatient basis.

    The data the researchers collected for each group included patient demographics, comorbidities, and complications within 90 days of surgery that required readmission to the hospital.

    Study Findings

    The annual prevalence of outpatient THA and TKA increased exponentially from 2010 to 2017, the researchers found, with a mean annual change of 15.8% in the outpatient THA group and 11.1% in the outpatient TKA group. Overall, patients discharged on the day they had surgery were younger and healthier, with fewer medical conditions such as diabetes and chronic pulmonary disease.

    No significant difference in complications requiring readmission to the hospital within 90 days was observed for the outpatient versus the inpatient THA groups. The TKA patients who were discharged the same day as surgery had a slightly higher odds ratio of complications requiring a hospital readmission. Overall, complications were not common in either TKA group, with an incidence of less than 1%.

    The study authors indicated that they believe same-day discharge following THA and TKA is safe but requires additional patient monitoring in the early postoperative period.

    Selecting the Right Patients

    Patient selection is also important for ensuring the best outcomes, Dr. Westrich said. Patients with heart or lung disease, diabetes, or sleep apnea are not generally good candidates for outpatient joint replacement, nor are smokers.

    Younger patients in their 40s through 60s tend to be better candidates, but those in their early 70s in good general health may also qualify.

    RELATED: CMS Is Removing THA from the Inpatient-Only List

    “Individuals considering same-day discharge should feel comfortable forgoing a night in the hospital where they would receive nursing care,” Dr. Westrich said. “A patient who is very anxious about surgery or experiences a great deal of stress about recovery may not be a good candidate.”

    Making an Informed Decision

    Dr. Westrich noted that the shift toward outpatient joint replacement has become more pronounced with the introduction of the Bundled Payment for Care Improvement by the Center for Medicare and Medicaid Services (CMS), which incentivizes reduction of non-essential hospital-associated costs and length of stay.

    In addition, the removal of primary THA and primary TKA from the Inpatient-Only List by CMS cleared the way for more outpatient procedures among Medicare beneficiaries.

    “Our study aimed to augment the literature on outpatient joint replacement surgery to help orthopaedic surgeons and their patients make an informed decision,” he said.

    “Although we found it can be performed safety and efficiently, it’s an option, not a requirement. Every patient is different, and individuals and their doctors should make an informed decision based on what makes patients feel most comfortable.”


    Debbi EM, Mosich GM, Bendich I, Kapadia M, Ast MP, Westrich GH. Same-day discharge total hip and knee arthroplasty: trends, complications, and readmission rates. J Arthroplasty. 2021 Nov 19;S0883-5403(21)00885-8. doi: 10.1016/j.arth.2021.11.023. Online ahead of print.