title: Micromotion of cementless tibial baseplates under physiological loading conditions.
abstract: Initial implant stability is crucial to cementless knee arthroplasty success. The objective of this study was to develop a physiological relevant methodology that incorporates torsion, shear, and compression forces to evaluate two tibial component designs that feature either a keel or cylindrical porous metal pegs. The data were compared with a simplified compression loading scenario. Results show a loading profile that combines compressive, shear, and torsional loads results in significantly larger motions than occur when loading in compression only. When comparing between a keeled and a pegged device, the new method shows significant differences in tibial component subsidence/liftoff at the anterior and posterior locations, which were lacking in the simplified test model. To accurately assess implant stability, studies should use physiological relevant loading.
authors.affiliation: Stryker Orthopaedics, Mahwah, NJ 07430, USA.
authors.forename: Safia
authors.initials: S
authors.lastname: Bhimji
authors.forename: R Michael
authors.initials: RM
authors.lastname: Meneghini
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D002102:Cadaver; D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control*; D007720:Knee Prosthesis; D008422:Materials Testing / Q000379:methods*; D011474:Prosthesis Design; D033081:Shear Strength; D013314:Stress, Mechanical; D013977:Tibia; D019415:Torque; D016474:Weight-Bearing