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J Knee Surg
DOI: 10.1055/a-2741-1586
Original Article

Inpatient Medicare TKA Patients Have Distinct Characteristics and Worse Outcomes: Implications for the New CMS PROMs Policy

Authors

  • Khaled A. Elmenawi

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States

  • Ignacio Pasqualini

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States

  • Benjamin E. Jevnikar

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States

  • Ahmed K. Emara

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States

  • Chao Zhang

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States

  • Nicolas S. Piuzzi 

    1   Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland, Ohio, United States
    2   Cleveland Clinic, Department of Biomedical Engineering, Cleveland, Ohio, United States
    • Cleveland Clinic Adult Reconstruction Research (CCARR) Group
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Abstract

The Centers for Medicare and Medicaid Services (CMS) recently mandated the collection of Patient-Reported Outcome-Based Performance Measures (PRO-PMs) for Medicare patients undergoing inpatient total knee arthroplasty (TKA). The policy's generalizability remains a concern. Therefore, we aimed to compare PROMs capture rates, patients' characteristics, and achieving the substantial clinical benefit (SCB) threshold between inpatient and outpatient Medicare TKA. A prospective cohort of Medicare patients aged ≥ 65 who underwent primary TKA between 2016 and 2022 at a single health system was analyzed (n = 7,926). Patients were categorized as inpatient (length of stay [LOS] > 24 hours, n = 2,812) or outpatient (LOS ≤ 24 hours, n = 5,114). Capture rates of CMS-mandated variables, baseline characteristics, and 1-year outcomes were compared. SCB was defined as a 20-point improvement in the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) per CMS criteria. Baseline capture rates were similar between groups (approximately 82.8%), but 1-year KOOS-JR completion was lower for inpatients (53.3% vs. 62.4%). Inpatients had higher comorbidity burden (CCI ≥ 2: 40% vs. 33%, p < 0.001), worse KOOS-JR (median 44.9 vs. 47.5, p < 0.001), lower VR-12 MCS scores (50.2 vs. 54.1, p < 0.001), and more frequent nonoperative joint pain (75.1% vs. 68.6%, p < 0.001) and back pain (67.4% vs. 63.8%, p < 0.001). Outpatients trended toward better SCB achievement (OR: 0.89, 95% CI: 0.78–1.00, p = 0.054). Compared to outpatients, inpatient Medicare TKA patients had lower 1-year PROM capture rates, more comorbidities, and worse baseline PROMs, with a trend toward not meeting CMS SCB thresholds. These differences highlight limitations in using inpatient-only data to assess national TKA outcomes, especially as outpatient procedures grow. Nonetheless, future studies with higher power should validate these findings. The level of evidence is III (retrospective).

Keywords

Medicare - total knee replacement - PROM

Ethical Approval

Our institutional review board committee approved this study.


Note

Cleveland Clinic Adult Reconstruction Research (CCARR) Group: Kurt P. Spindler, MD, Trevor G. Murray, MD, Robert M. Molloy, MD, Kim L. Stearns, MD, Viktor E. Krebs, MD, Nicholas R. Scarcella, MD, Michael Erossy, MD, Alexander L. Roth, MD, Matthew E. Deren, MD, Michael R. Bloomfield, MD, Carlos A. Higuera, MD, John P. McLaughlin, DO, Peter A. Surace, MD.




Publication History

Received: 07 May 2025

Accepted: 06 November 2025

Article published online:
24 November 2025

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