title: Accuracy of Low Dose Computed Tomography Scanogram for Measurement of Femoral Version after Locked Intramedullary Nailing.
abstract: This prospective study was performed to compare the accuracy of femoral version measurements following repair of femoral shaft fractures using computed tomography (CT) scanograms with 10 % of the standard dose of ionizing radiation versus standard-dose scanograms.
  
  
  
  CT scanogram protocols that used 90 and 10 % of the usual dose of ionizing radiation were developed. Ten patients with comminuted femoral shaft fractures repaired with either an intramedullary (IM) nail or plate were imaged with both high- and low-dose CT scanograms. Postoperative version of both femurs was measured and compared between the two dose scans using the Bonesetter application. This was a prospective blinded controlled study at a level 1 trauma centre. Statistical analysis was performed, including standard deviation (SD) and paired t test. Significance was set at p < 0.05.
  
  
  
  Comparison of femoral version measurements between the 90 and 10 % dose scanograms on the native and repaired sides were insignificant (p = 0.870 and p = 0.737, respectively). The difference between native and repaired femurs had an average error of 2.0 ± 1.1° for both the high- and low-dose scans and was insignificant (p = 0.742).
  
  
  
  Reducing the dose of ionizing radiation in a CT scanogram by 90 % has no significant effect on the accuracy of femoral version measurement. This simple change can significantly reduce patient radiation exposure while accurately measuring femoral version and length.
authors.affiliation: Department of Orthopaedic Surgery, Detroit Medical centre/Wayne State University, 4201 St.Antoine, UHC 6A, Detroit, MI, 48201, USA. KHultman@dmc.org.
authors.forename: Kristi Lynn
authors.initials: KL
authors.lastname: Hultman
authors.affiliation: Department of Orthopaedic Surgery, Detroit Medical centre/Wayne State University, 4201 St.Antoine, UHC 6A, Detroit, MI, 48201, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Vaidya
authors.affiliation: Department of Urology, Detroit Medical centre, Detroit, MI, USA.
authors.forename: Ibraheem
authors.initials: I
authors.lastname: Malkawi
authors.affiliation: Department of Orthopaedic Surgery, Detroit Medical centre/Wayne State University, 4201 St.Antoine, UHC 6A, Detroit, MI, 48201, USA.
authors.forename: Jon Brandon
authors.initials: JB
authors.lastname: Carlson
authors.affiliation: Department of Urology, Detroit Medical centre, Detroit, MI, USA.
authors.forename: Jason Benjamin
authors.initials: JB
authors.lastname: Wynberg
mesh_terms: D005264:Femoral Fractures; D005269:Femur / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary; D006801:Humans; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed
keywords: Anteversion; CT scanogram; Femoral version; Femur fracture; Intramedullary nail