title: In vitro analysis of exeter stem torsional stability.
abstract: The effect of cyclic loading on the torsional stiffness of a polished double-tapered femoral stem was investigated in vitro. Initial torsional stability was compared with torsional stability after cyclic loading. Stems were removed from the cement mantle and reinserted without the use of additional cement. Torsional stability was measured after reinsertion and after further cyclic loading. Subsidence of the stem was observed. No difference in torsional stiffness was observed during loading. No difference between the stiffness before extraction and after reinsertion was observed. Torsional stiffness of an Exeter stem does not decrease after axial subsidence under cyclic loading. Stability is retained after reinsertion into the original cement mantle. Debonding of the Exeter stem is not associated with rotational instability of the implant.
authors.affiliation: School of Engineering Systems and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors.forename: Cameron Gordon Roodveldt
authors.initials: CG
authors.lastname: Bell
authors.forename: Patrick
authors.initials: P
authors.lastname: Weinrauch
authors.forename: Mark
authors.initials: M
authors.lastname: Pearcy
authors.forename: Ross
authors.initials: R
authors.lastname: Crawford
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001843:Bone Cements; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D013314:Stress, Mechanical; D054159:Torsion, Mechanical
chemical_list: D001843:Bone Cements