title: [Are angle-fixed implants with elastic properties advantageous for the internal fixation of proximal humerus fractures?].
abstract: There is a recent interest for the use of angle-fixed plates in the management of proximal humerus fractures. Rigid implants might be associated with an increased risk of cutting-out. In order to analyse the potential beneficial effects of the implant elasticity on fracture fixation, the biomechanical properties of a rigid and an elastic angle-fixed plating system were assessed in an experimental study. An unstable fracture of the surgical neck was created in 8 pairs of human humeri. Specimens were subjected to axial loading and torque. Stiffness, subsidence and load to failure were assessed. The implant with elastic properties was characterized by a lower torsional stiffness and a higher subsidence during axial loading and torque. This implant failed at lower loads than the rigid implant did. Elastic implant properties of angle-fixed plates have shown not to be advantageous for the management of fractures of the proximal humerus.
authors.affiliation: Klinik und Poliklinik für Unfallchirurgie der Johannes Gutenberg-Universität, Mainz. Hessmann@unfall.klinik.uni-mainz.de
authors.forename: M H
authors.initials: MH
authors.lastname: Hessmann
authors.forename: W
authors.initials: W
authors.lastname: Sternstein
authors.forename: D
authors.initials: D
authors.lastname: Mehler
authors.forename: J
authors.initials: J
authors.lastname: Korner
authors.forename: A
authors.initials: A
authors.lastname: Hofmann
authors.forename: P M
authors.initials: PM
authors.lastname: Rommens
mesh_terms: D001860:Bone Plates; D001863:Bone Screws; D019245:Compressive Strength; D004548:Elasticity; D019544:Equipment Failure Analysis; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D011475:Prosthesis Failure; D012784:Shoulder Fractures / Q000503:physiopathology* / Q000601:surgery*; D013718:Tensile Strength; D019415:Torque