0
Scientific Articles   |    
Biomechanical Evaluation of Periprosthetic Femoral Fracture Fixation
Rad Zdero, PhD1; Richard Walker, MD2; James P. Waddell, MD, FRCS(C)2; Emil H. Schemitsch, MD, FRCS(C)2
1 Martin Orthopaedic Biomechanics Laboratory, Shuter Wing (Room 5-066), St. Michael's Hospital, 30 Bond Street, Toronto, ON L5G-456, Canada
2 Division of Orthopaedics, Department of Surgery, University of Toronto, St. Michael's Hospital, Suite 800, 55 Queen Street East, Toronto, ON M5C 1R6, Canada. E-mail address for E.H. Schemitsch: schemitsche@smh.toronto.on.ca
View Disclosures and Other Information
Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.
Investigation performed at the Martin Orthopaedic Biomechanics Laboratory, St. Michael's Hospital, Toronto, and the Division of Orthopaedics, Department of Surgery, University of Toronto, Toronto, Ontario, Canada

The Journal of Bone and Joint Surgery, Inc.
J Bone Joint Surg Am, 2008 May 01;90(5):1068-1077. doi: 10.2106/JBJS.F.01561
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Abstract

Background: A variety of methods are available for the fixation of femoral shaft fractures after total hip arthroplasty. However, few studies in the literature have quantified the performance of such repair constructs. The aim of this study was to evaluate biomechanically four different constructs for the fixation of periprosthetic femoral shaft fractures following total hip arthroplasty.

Methods: Twenty synthetic femora were tested in axial compression, lateral bending, and torsion to determine initial stiffness, as well as stiffness following fixation of a simulated femoral midshaft fracture with and without a bone gap. Four fracture fixation constructs (five specimens per group) were assessed: construct A was a Synthes locked plate (a twelve-hole broad dynamic compression plate) with locked screws; construct B, a Synthes locked plate (a twelve-hole broad dynamic compression plate) with cables and locked screws; construct C, a Zimmer nonlocking (eight-hole) cable plate with cables and nonlocked screws; and construct D, a Zimmer nonlocking (eight-hole) cable plate with allograft strut, cables, and nonlocked screws. Axial stiffness, lateral bending stiffness, and torsional stiffness were assessed with respect to baseline intact specimen values. Axial load to failure was also measured for the specimens.

Results: Construct D demonstrated either equivalent or superior stiffness in all testing modes compared with the other constructs in femora with both a midshaft fracture and a bone gap. A comparison of constructs A, B, and C demonstrated equivalent stiffness in all test modes (with one exception) in femora with a midshaft fracture and a bone gap.

Conclusions: A combination of a nonlocking plate with an allograft strut (construct D) resulted in the highest stiffness of the constructs examined for treating a periprosthetic fracture around a stable femoral component of a total hip replacement.

Clinical Relevance: A locked plate (constructs A and B) should be used with caution as a stand-alone treatment for the fixation of a periprosthetic femoral shaft fracture following total hip arthroplasty, particularly with good bone stock.

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





    Werner Kolb, MD
    Posted on October 05, 2008
    Locking Compression Plate Fixation for Periprosthetic Femoral Fracture
    Orthopaedic practice

    To the Editor:

    We read the article by Zdero and colleagues(1) with great interest. We have used the LCP for six years and find that it offers several advantages over larger constructs. Biologically, in addition to the wider exposure of the bone, larger implant-bone contact will result in a reduction of bone perfusion, as bone receives its blood supply through the periosteal and endosteal lining.(2). We would also offer some technical tips on use of the LCP.

    The biomechanical advantages of internal fixators include the ability to use longer splints with less pullout force and a larger distance between the two screws adjacent to the fracture, which allows for lower elastic deformation of the plate and the interfragmentary tissue. Screw to plate hole ratios of less than 0.5 create a long lever arm and decrease the bending loads on the distal screws.(3) An 18-24 hole plate in the femur with few screws should be used to increase the lever arm and distribute the bending forces.(4)

    3) If the vascularity of bone and surrounding soft tissue has not been overly disturbed, the physiological response to this relatively flexible construct is rapid callus formation that bridges the fragments, as occurs in nonoperative treatment or after intramedullary nailing.(5)

    The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.

    References

    1. Rad Zdero, Richard Walker, James P. Waddell, and Emil H. Schemitsch Biomechanical Evaluation of Periprosthetic Femoral Fracture Fixation J Bone Joint Surg Am 2008; 90: 1068-1077

    2. Keita I, Perren SM. Biology and biomechanics in bone healing. In Rüedi TP, Buckley RE, Moran CG, editors. AO principles of fracture management, Vol. 1-principles. New York: Thieme;2007:9-31.

    3. Field JR. Törnkvist H, Hearn TC, Sumner-Smith G, Woodside TD. The influence of screw omission on construction stiffness and bone surface strain in the application of bone plates to cadaveric bone. Injury 1999;30:591-598.

    4. Gautier E, Sommer C. Guidlines for the application of the LCP. Injury 2003; 34 Suppl 2: B63-76.

    5. Lorich DG, Gardner MJ. Plates. In Rüedi TP, Buckley RE, Moran CG, editors. AO principles of fracture management, Vol. 1-principles. New York: Thieme;2007:227-247.

    Related Content
    The Journal of Bone & Joint Surgery
    JBJS Case Connector
    Topic Collections
    Hip
    Related Audio and Videos
    PubMed Articles
    Guidelines
    Treatment of pediatric diaphyseal femur fractures. -American Academy of Orthopaedic Surgeons (AAOS)
    Results provided by:
    PubMed
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    01/08/2014
    Pennsylvania - Penn State Milton S. Hershey Medical Center
    11/15/2013
    Louisiana - Ochsner Health System
    05/03/2012
    California - UCLA/OH Department of Orthopaedic Surgery