0
Scientific Articles   |    
Surgeon, Implant, and Patient Variables May Explain Variability in Early Revision Rates Reported for Unicompartmental Arthroplasty
Stefano Bini, MD1; Monti Khatod, MD2; Guy Cafri, PhD3; Yuexin Chen, BS3; Elizabeth W. Paxton, MA3
1 Kaiser Permanente, 280 West MacArthur Boulevard, Oakland, CA 94611
2 Kaiser Permanente, 1011 Baldwin Park Boulevard, Baldwin Park, CA 91706
3 Kaiser Permanente, 3033 Bunker Hill Street, San Diego, CA 92109
View Disclosures and Other Information
  • Disclosure statement for author(s): PDF

Investigation performed at Kaiser Permanente, Oakland, Baldwin Park, and San Diego, California



Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.

Copyright © 2013 by The Journal of Bone and Joint Surgery, Inc.
J Bone Joint Surg Am, 2013 Dec 18;95(24):2195-2202. doi: 10.2106/JBJS.L.01006
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Abstract

Background: 

The reported revision rates for cemented unicompartmental knee arthroplasties have varied widely. The effect of implant selection, patient characteristics, and surgeon characteristics on revision risk has not been evaluated fully. The purpose of the present study was to determine the impact of these variables on the risk for aseptic revision arthroplasty.

Methods: 

We identified all cemented primary unicompartmental knee arthroplasties performed in our health-care system from 2002 to 2009 (median follow-up time = 2.6 years) to assess the risk for aseptic revision. A multivariate marginal Cox proportional-hazards model with robust standard errors (to adjust for the nesting of surgical cases within surgeons) was used to calculate the differential risk for revision of implants after adjusting for surgeon and hospital volume of unicompartmental knee arthroplasties performed; surgeon experience with unicompartmental knee arthroplasties at the time of surgery; surgeon fellowship training; and patient age, sex, weight, body mass index, and American Society of Anesthesiologists (ASA) score.

Results: 

A total of 1746 unicompartmental knee arthroplasties were identified. The overall revision rate during the study period was 4.98% (95% confidence interval [CI], 4.0% to 6.1%). In a multivariate Cox model, the hazard ratio (HR) for aseptic revision relative to a modern, fixed, metal-backed tibial bearing was significantly higher for an all-polyethylene tibial tray (HR = 3.85, 95% CI = 1.54 to 9.63, p = 0.004) but not significantly higher for a mobile-bearing implant (HR = 2.42, 95% CI = 0.55 to 10.65, p = 0.242) or an older-design, fixed, metal-backed bearing (HR = 1.89, 95% CI = 0.67 to 5.33, p = 0.23). Younger age was associated with increased risk (age less than fifty-five years compared with more than sixty-five years: HR = 4.83, 95% CI = 2.60 to 8.96, p < 0.001), and a higher ASA score (≥3 compared with <3 points: HR = 0.54, 95% CI = 0.32 to 0.93, p = 0.027) and a greater mean yearly surgeon volume of unicompartmental knee arthroplasties (twelve or fewer compared with more than twelve: HR = 2.18, 95% CI = 1.28 to 3.74, p = 0.004) were associated with reduced risk.

Conclusions: 

Implant selection can have a considerable effect on the risk for aseptic revision following a cemented unicompartmental knee arthroplasty, as can patient and surgeon factors. Therefore, the variation among risk estimates reported in the literature for unicompartmental knee arthroplasty revision may be explained by differences in patient characteristics and implant selection as well as the surgeons’ yearly volume of unicompartmental knee arthroplasties.

Level of Evidence: 

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Figures in this Article
    Sign In to Your Personal ProfileSign In To Access Full Content
    Not a Subscriber?
    Get online access for 30 days for $35
    New to JBJS?
    Sign up for a full subscription to both the print and online editions
    Register for a FREE limited account to get full access to all CME activities, to comment on public articles, or to sign up for alerts.
    Register for a FREE limited account to get full access to all CME activities
    Have a subscription to the print edition?
    Current subscribers to The Journal of Bone & Joint Surgery in either the print or quarterly DVD formats receive free online access to JBJS.org.
    Forgot your password?
    Enter your username and email address. We'll send you a reminder to the email address on record.

     
    Forgot your username or need assistance? Please contact customer service at subs@jbjs.org. If your access is provided
    by your institution, please contact you librarian or administrator for username and password information. Institutional
    administrators, to reset your institution's master username or password, please contact subs@jbjs.org

    References

    Accreditation Statement
    These activities have been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of the American Academy of Orthopaedic Surgeons and The Journal of Bone and Joint Surgery, Inc. The American Academy of Orthopaedic Surgeons is accredited by the ACCME to provide continuing medical education for physicians.
    CME Activities Associated with This Article
    Submit a Comment
    Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
    Comments are moderated and will appear on the site at the discretion of JBJS editorial staff.

    * = Required Field
    (if multiple authors, separate names by comma)
    Example: John Doe





    Related Content
    The Journal of Bone & Joint Surgery
    JBJS Case Connector
    Topic Collections
    Related Audio and Videos
    PubMed Articles
    Guidelines
    The treatment of glenohumeral joint osteoarthritis. -American Academy of Orthopaedic Surgeons (AAOS) | 9/11/2009
    Results provided by:
    PubMed
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    02/05/2014
    Oregon - The Center - Orthopedic and Neurosurgical Care and Research
    04/16/2014
    Ohio - OhioHealth Research and Innovation Institute (OHRI)