title: Evaluation of a polyaxial angle-stable volar plate in a distal radius C-fracture model--a biomechanical study.
abstract: BACKGROUND
  Polyaxial angle-stable plating is thought to be particularly beneficial in the management of complex intra-articular fractures of the distal radius. The purpose of the present study was to investigate whether the technique provides stability to match that of conventional (fixed-angle) angle-stable constructs.
  
  
  METHODS
  In seven pairs of human cadaver radii, an Arbeitsgemeinschaft für Osteosynthese (AO) 23 C2.1 intra-articular fracture was created. One radius of each pair received a juxta-articular 2.4-mm locking compression plate (LCP) Volar Distal Radius Plate, whilst the contralateral one received a 2.4-mm Variable Angle Locking Compression Plate (LCP) Two-Column Volar Distal Radius Plate (both plates: Synthes, Oberdorf, Switzerland). Parameters tested were construct stiffness (static axial loading with 150 N), range of motion and secondary loss of reduction (dynamic 150 N axial loading over 5000 cycles). Stiffness and range of motion were measured both pre- and post-cycling.
  
  
  RESULTS
  The polyaxial constructs were significantly stiffer, both before and after cyclic testing. However, the two-column plates showed a significant loss of stiffness during cyclic testing. The range of motion was significantly greater, both initially and at the end of cyclic testing, in the fixed-angle constructs. The conventional constructs had significantly greater secondary loss of reduction.
  
  
  CONCLUSIONS
  The polyaxial two-column plate tested in this study provides a biomechanically sound construct for the management of intra-articular fractures of the distal radius.
authors.affiliation: Department of Traumatology, Hand and Reconstructive Surgery, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena, Germany. Sascha.rausch@med.uni-jena.de
authors.forename: Sascha
authors.initials: S
authors.lastname: Rausch
authors.forename: Kajetan
authors.initials: K
authors.lastname: Klos
authors.forename: Helen
authors.initials: H
authors.lastname: Stephan
authors.forename: Konrad
authors.initials: K
authors.lastname: Hoffmeier
authors.forename: Florian
authors.initials: F
authors.lastname: Gras
authors.forename: Markus
authors.initials: M
authors.lastname: Windolf
authors.forename: Boyko
authors.initials: B
authors.lastname: Gueorguiev
authors.forename: Gunther O
authors.initials: GO
authors.lastname: Hofmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Mückley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D057072:Intra-Articular Fractures / Q000601:surgery*; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D008954:Models, Biological; D011885:Radius Fractures / Q000601:surgery*; D016059:Range of Motion, Articular; D014955:Wrist Joint / Q000601:surgery*