The Journal of Bone and Joint Surgery (American). 2008;90:1068-1077.
doi:10.2106/JBJS.F.01561
© 2008 The Journal of Bone and Joint Surgery, Inc.
Biomechanical Evaluation of Periprosthetic Femoral Fracture Fixation
Rad Zdero, PhD1,
Richard Walker, MD2,
James P. Waddell, MD, FRCS(C)2 and
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{at}smh.toronto.on.ca
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
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.
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.

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Letters to the Editor:
Read all Letters to the Editor
- Locking Compression Plate Fixation for Periprosthetic Femoral Fracture
- Werner Kolb, MD, et al.
- JBJS Online, 6 Oct 2008
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