title: Percutaneous iliosacral fixation in external rotational pelvic fractures. A biomechanical analysis.
abstract: BACKGROUND
  Although the gold standard in open book pelvic fractures remains the pubic symphysis (PS) plate fixation, the clinical outcomes are not satisfactory, despite the excellent anatomical reduction assessed radiologically. Some authors suggest that residual instability of the posterior pelvic elements may be responsible for the chronic pain and the early osteoarthritic changes in the sacroiliac joint (SIJ).
  
  
  OBJECTIVE
  To evaluate whether the isolated posterior fixation with one or two iliosacral screws (ISSs) is sufficient to provide adequate stability for the treatment of Burgess Young APC-II (YB APC-II) type of pelvic ring injuries.
  
  
  METHODS
  Biomechanical experimental study using 7 fresh human pelvises, where an YB APC-II pelvic injury was previously implemented. The isolated posterior fixation of the pelvic ring with 1 or 2 ISSs directed in the S1 vertebra body was analysed in each specimen following an axial load of 300N. The different displacement of the SIJ and of the PS were analysed in all three spatial axes, using the validated optical measurement system 3D PONTOS 5M. A multivariate version of Friedman test (non-parametric ANOVA for repeated measures) was performed.
  
  
  RESULTS
  The isolated fixation of the SIJ with 1 ISS did not show any differences with respect to the intact pelvis (p=0.851). Regarding the PS, both type of fixations (with 1 or 2 ISSs) confirmed an acceptable correction and adequate control of the PS even though with some differences compared to the intact pelvis (p=0.01). The presence of the second ISS found not to offer any significant additional benefit. The three-dimensional analysis of the behaviour of the pelvic elements, in these two different types of fixation, did not show any statistical significant differences (p=0.645).
  
  
  CONCLUSIONS
  The posterior fixation with ISS can represent an alternative option for treatment of pelvic injuries associated with rotational instability. Further prospective clinical studies are necessary to determine, the influence of the residual pubic symphysis mobility in the every day life, when the above-mentioned technique is applied.
authors.affiliation: Clinical Orthopaedics, Trauma Surgery and Rheumatology Management Unit, Hospital Universitario Virgen del Rocío, Seville, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Giráldez-Sánchez
authors.affiliation: Clinical Orthopaedics, Trauma Surgery and Rheumatology Management Unit, Hospital Universitario Virgen del Rocío, Seville, Spain.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Lázaro-Gonzálvez
authors.affiliation: Department of Mechanical Engineering, University of Seville, Escuela Superior de Ingenieros, Seville, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Martínez-Reina
authors.affiliation: Clinical Orthopaedics, Trauma Surgery and Rheumatology Management Unit, Hospital Universitario Virgen del Rocío, Seville, Spain. Electronic address: serranotoledano@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Serrano-Toledano
authors.affiliation: Department of Mechanical Engineering, University of Seville, Escuela Superior de Ingenieros, Seville, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Navarro-Robles
authors.affiliation: Clinical Orthopaedics, Trauma Surgery and Rheumatology Management Unit, Hospital Universitario Virgen del Rocío, Seville, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cano-Luis
authors.affiliation: Academic Department of Trauma and Orthopaedics, Clarendon Wing, Level A, Leeds General Infirmary Great George Street, LS1 3EX Leeds, UK.
authors.forename: Evangelos M
authors.initials: EM
authors.lastname: Fragkakis
authors.affiliation: Academic Department of Trauma and Orthopaedics, Clarendon Wing, Level A, Leeds General Infirmary Great George Street, LS1 3EX Leeds, UK.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Giannoudis
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D002102:Cadaver; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D050723:Fractures, Bone / Q000473:pathology / Q000601:surgery*; D006801:Humans; D010384:Pelvic Bones / Q000293:injuries / Q000473:pathology / Q000601:surgery*; D011631:Pubic Symphysis / Q000473:pathology / Q000601:surgery*; D012447:Sacrum / Q000293:injuries / Q000473:pathology / Q000601:surgery*
keywords: Biomechanic; Minimally invasive fixation; Open-book fracture; Pelvis; Screw; Young-Burgess fracture