title: Anatomical variations of the proximal radius and their effects on osteosynthesis.
abstract: OBJECTIVE
  In fractures of the radial head and neck requiring open reduction and internal fixation, osteosynthesis may be safely applied in a limited zone. We conducted a morphometric study of the proximal radius at the level of the safe zone to identify different morphologic types of this anatomical region.
  
  
  METHODS
  We analyzed 44 dried cadaveric radii. We measured the whole length of the radius, the length of the neck and head, and the minimum and maximum diameter of the radial head. The morphologic aspect of the neck-head curvature of the safe zone was evaluated qualitatively and quantitatively.
  
  
  RESULTS
  The proximal radius at the level of the safe zone exhibited different radii of bending. In particular, we identified a morphologic type A, which showed a flat profile (25% of cases), morphologic types B and C, which showed a low concave curvature (64%), and a marked concave curvature (11%), respectively, of the safe zone.
  
  
  CONCLUSIONS
  The profile of the proximal radius in the safe zone shows substantial morphologic variations that should be taken into account when operating on fractures of the proximal radius, to avoid malunions, pain, and stiffness of the elbow joint. A preoperative radiograph of the contralateral uninjured radius may be helpful in selecting the most appropriate internal fixation device to reconstruct the proximal radius after comminuted fractures.
  
  
  CONCLUSIONS
  Knowledge of the proper bending radius of the safe zone allows the surgeon to select the most appropriate plate, and to achieve good fracture reduction and anatomical restoration of the proximal radius.
authors.affiliation: Department of Orthopaedic Surgery and Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy. federicomariasacchetti@hotmail.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Giannicola
authors.forename: Erica
authors.initials: E
authors.lastname: Manauzzi
authors.forename: Federico M
authors.initials: FM
authors.lastname: Sacchetti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Greco
authors.forename: Gianluca
authors.initials: G
authors.lastname: Bullitta
authors.forename: Annarita
authors.initials: A
authors.lastname: Vestri
authors.forename: Gianluca
authors.initials: G
authors.lastname: Cinotti
mesh_terms: D001860:Bone Plates; D002102:Cadaver; D016009:Chi-Square Distribution; D005593:Fracture Fixation, Internal / Q000379:methods; D006801:Humans; D011884:Radius / Q000033:anatomy & histology* / Q000601:surgery; D011885:Radius Fractures / Q000601:surgery; D018709:Statistics, Nonparametric