title: Simultaneous and multisite measure of micromotion, subsidence and gap to evaluate femoral stem stability.
abstract: The initial stability of cementless femoral components is crucial for the long-term success of total hip arthroplasty. This has been reported in animal and clinical studies. Until now, the stability was evaluated by the measurement of relative micromotion on a few simultaneous locations around the stem in cadaveric experiments. This paper presents an extended experimental setup to measure simultaneously local micromotion, subsidence and gap on hundreds of points at the bone-stem interface. This technique we applied to anatomical and straight stems in three pairs of cadaveric femurs. Measurements were in agreement with typically reported values. Conversely to other methods, which measure micromotion between implant and bone anchoring points of the measuring device, our method provides local micromotion between stem surface and adjacent bone surface. The observed variation of micromotion at the peri-implant surface confirms the importance of this simultaneous measure on a lot of points around the implant.
authors.affiliation: Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Gortchacow
authors.forename: Michael
authors.initials: M
authors.lastname: Wettstein
authors.forename: Dominique P
authors.initials: DP
authors.lastname: Pioletti
authors.forename: Magdalena
authors.initials: M
authors.lastname: Müller-Gerbl
authors.forename: Alexandre
authors.initials: A
authors.lastname: Terrier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements; D002102:Cadaver; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology* / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D066298:In Vitro Techniques; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology; D009038:Motion; D011474:Prosthesis Design; D011475:Prosthesis Failure; D033081:Shear Strength / Q000502:physiology; D055114:X-Ray Microtomography
chemical_list: D001843:Bone Cements