Articles   |    
Determination of Polyethylene Wear in Total Hip Replacements with Use of Digital Radiographs*
View Disclosures and Other Information
Investigation performed at the Section of Orthopaedic Surgery and Rehabilitation Medicine, Department of Surgery, The University of Chicago, Chicago
J Bone Joint Surg Am, 1997 Nov 01;79(11):1635-41
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case


We describe a computer-assisted vector wear technique for the determination of polyethylene wear on digital radiographs. Twenty-five hips that had had a total hip arthroplasty were used to evaluate the repeatability and performance of three radiographic techniques to measure wear of the acetabular polyethylene liner: the manual technique with use of calipers described by Livermore et al., the same technique with use of a digitizing tablet, and our new technique of computer-assisted vector wear analysis. We found our new technique to be at least ten times more repeatable than the technique with use of either calipers or a digitizing tablet.Fourteen of the polyethylene liners were retrieved at autopsy, and the actual measurements of wear of those liners were compared with the measurements that had been obtained with the three radiographic techniques of wear analysis. Computer-assisted vector wear analysis outperformed the manual techniques of Livermore et al. When compared with the data obtained from the specimens retrieved at autopsy, the measurement of wear determined with the computer-assisted technique differed by an average of 0.08 millimeter, whereas the measurements obtained with use of calipers and use of a digitizing tablet differed by 0.26 and 0.25 millimeter, respectively.The performance of computer-assisted vector wear analysis in the clinical setting was evaluated with use of controls with known amounts of wear. These were mounted in pelvic phantoms, and radiographs were made with use of a setup that simulated the clinical setting. Analysis of nine controls with 2.0 millimeters of wear yielded an average measurement of wear (and a standard deviation) of 1.99 ± 0.21 millimeters.CLINICAL RELEVANCE: Computer-assisted vector wear analysis demonstrated superior repeatability and accuracy compared with current techniques of manual analysis. Improved repeatability and accuracy in the determination of polyethylene wear should facilitate the investigation of factors related to the prosthesis and to the patient that affect the rates of wear.

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


    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
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    Pennsylvania - Penn State Milton S. Hershey Medical Center
    Louisiana - Ochsner Health System