title: Does the lateral plate need to overlap the stem to mitigate stress concentration when treating Vancouver C periprosthetic supracondylar femur fracture?
abstract: The effect of construct length on cortical strain and load to failure between locked compression plating and cemented femoral stem in a fall model was analyzed. Eight Sawbone femurs with cemented stems were instrumented with increasing fixation lengths starting 8cm distal to stem tip and progressing proximally to overlapping constructs. Uniaxial strain gauges measured cortical strain. Load to failure was performed with 8cm gap between implants, 2cm gap, and proximally overlapping configurations. Strain was significantly reduced as the 8cm gap transitioned to an overlapped construct with most comparisons. Load to failure in the overlapped construct was 273% greater compared to 2cm gap construct. Overlapping the stem with a locking compression plate resulted in reduced strain and increased load to failure.
authors.affiliation: Department of Orthopaedics, University of Utah, Salt Lake City, UT.
authors.forename: Erik N
authors.initials: EN
authors.lastname: Kubiak
authors.affiliation: Department of Orthopaedics, University of Utah, Salt Lake City, UT.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Haller
authors.affiliation: Department of Orthopaedics, University of Utah, Salt Lake City, UT.
authors.forename: Dan D
authors.initials: DD
authors.lastname: Kemper
authors.affiliation: Division of Epidemiology, Department of Medicine, University of Utah, Salt Lake City, UT.
authors.forename: Angela P
authors.initials: AP
authors.lastname: Presson
authors.affiliation: Department of Orthopaedics, University of Utah, Salt Lake City, UT.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Higgins
authors.affiliation: Department of Geisinger Health, System, Danville, PA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Horwitz
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D005264:Femoral Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006622:Hip Prosthesis; D008953:Models, Anatomic; D057068:Periprosthetic Fractures / Q000601:surgery*; D013314:Stress, Mechanical
keywords: biomechanics; cortical strain; locked plate; periprosthetic fractures; total hip arthroplasty