title: Dual plating for fixation of humeral shaft fractures: A mechanical comparison of various combinations of plate lengths.
abstract: OBJECTIVE
  The role of plate configuration was found inconclusive on the biomechanical effects of the plate size and hole number for dual plate constructions in humeral shaft fractures. The purpose of this study was to test the biomechanical stability of various dual plate constructions.
  
  
  METHODS
  Twenty-four left humeri (4th Generation Composite Humerus, Sawbones, Malmö, Sweden) with comminuted midshaft humeral fracture were used. Four groups of plate constructs were tested: laterally fixed 8-hole locking plate and screws were combined with anteriorly locking plates containing 0, 4, 6, or 8 holes in groups I, II, III, and IV, respectively. The alterations in axial, bending, and torsional angles were recorded.
  
  
  RESULTS
  There were no fixation failures during axial, bending, or torsional stiffness testing within the elastic behavior limits. Axial stiffness was highest in Group IV. Torsional stiffness, posterior-to-anterior bending stiffness, lateral-to-medial bending stiffness, and medial-to-lateral bending stiffness were lowest in Group I.
  
  
  CONCLUSIONS
  The similar stiffness values for the 8-to-4 hole and 8-to-6 hole plate constructions indicate that the 8-to-4 hole construction is an option in young adults, while the stiffest 8-to-8 hole combination may be an option for osteoporotic patients.
authors.affiliation: Dokuz Eylul University, Faculty of Medicine, Dept. Orthopaedics and Traumatology, Izmir, Turkey. Electronic address: karakasliahmet@gmail.com.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Karakasli
authors.affiliation: Dokuz Eylul University, Faculty of Medicine, Dept. Orthopaedics and Traumatology, Izmir, Turkey. Electronic address: dronurbasci@gmail.com.
authors.forename: Onur
authors.initials: O
authors.lastname: Basci
authors.affiliation: Dokuz Eylul University, Institute of Health Sciences, Dept. Biomechanics, Izmir, Turkey. Electronic address: fatih_ertem@hotmail.com.
authors.forename: Fatih
authors.initials: F
authors.lastname: Ertem
authors.affiliation: Karatas Hospital, Izmir, Turkey.
authors.forename: Eyad
authors.initials: E
authors.lastname: Sekik
authors.affiliation: Dokuz Eylul University, Faculty of Medicine, Dept. Orthopaedics and Traumatology, Izmir, Turkey. Electronic address: hasan.havitcioglu@deu.edu.tr.
authors.forename: Hasan
authors.initials: H
authors.lastname: Havitcioglu
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D005593:Fracture Fixation, Internal / Q000379:methods*; D018460:Fractures, Comminuted / Q000601:surgery*; D006801:Humans; D006810:Humeral Fractures / Q000601:surgery*; D008422:Materials Testing; D011474:Prosthesis Design; D013314:Stress, Mechanical; D013548:Sweden
keywords: Dual plate; Fixation; Humeral shaft fractures