title: Influence of the stem fixation scenario on load transfer in a hip resurfacing arthroplasty with a biomimetic stem.
abstract: Finite element (FE) analysis is a widely used tool for extensive preclinical testing of orthopaedic implants such as hip resurfacing femoral components, including evaluation of different stem fixation scenarios (cementation vs osseointegration, etc.). Most FE models use surface-to-surface contact elements to model the load-bearing interfaces that connect bone, cement and implant and neglect the mechanical effects of phenomena such as residual stresses from bone cement curing. The objective of the current study is to evaluate and quantify the effect of different stem fixation scenarios and related phenomena such as residual stresses from bone cement curing. Four models of a previously clinically available implant (Durom) were used to model different stem fixation scenarios of a new biomimetic stem: a cemented stem, a frictional stem, a partially and completely bonded stem, with and without residual stresses from bone cement curing. For the frictional stem, stem-bone micromotions were increased from 0% to 61% of the available surface subjected to micromotions between 10 and 40μm with the inclusion of residual stresses from bone cement curing. Bonding the stem, even partially, increased stress in the implant at the stem-head junction. Complete bonding of the stem decreased bone strain at step tip, at the cost of increased strain shielding when compared with the frictional stem and partially bonded stem. The increase of micromotions and changes in bone strain highlighted the influence of interfacial conditions on load transfer, and the need for a better modeling method, one capable of assessing the effect of phenomena such as interdigitation and residual stresses from bone cement curing.
authors: Laboratoire de recherche en Imagerie et Orthopédie (LIO), École de technologie supérieure, Montréal, QC, Canada.
authors: C
authors: C
authors: Caouette
authors: Advanced Polymer Composites Research Group, National Research Council of Canada (NRC), Boucherville, QC, Canada.
authors: M N
authors: MN
authors: Bureau
authors: Maisonneuve-Rosemont Hospital, University of Montreal, Montreal, QC, Canada.
authors: P-A
authors: PA
authors: Vendittoli
authors: Maisonneuve-Rosemont Hospital, University of Montreal, Montreal, QC, Canada.
authors: M
authors: M
authors: Lavigne
authors: Laboratoire de recherche en Imagerie et Orthopédie (LIO), École de technologie supérieure, Montréal, QC, Canada. Electronic address: natalia.nuno@etsmtl.ca.
authors: N
authors: N
authors: Nuño
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D032701:Biomimetics / Q000295:instrumentation*; D001843:Bone Cements; D015519:Bone Density; D016723:Bone Remodeling; D005269:Femur / Q000502:physiology / Q000601:surgery; D020342:Finite Element Analysis; D006622:Hip Prosthesis; D006801:Humans; D060489:Prosthesis Retention / Q000379:methods*; D013314:Stress, Mechanical; D016474:Weight-Bearing
chemical_list: D001843:Bone Cements
keywords: Bone cement curing; Finite element analysis; Hip resurfacing prosthesis; Load-bearing interface