title: Computed tomography for suspected scaphoid fractures: comparison of reformations in the plane of the wrist versus the long axis of the scaphoid.
abstract: BACKGROUND
  Definitive diagnosis of occult scaphoid fractures remains difficult. We tested the null hypothesis that, for diagnosis of true fractures among suspected scaphoid fractures, computed tomography (CT) reformations along the long axis of the scaphoid have the same accuracy as reformations made relative to the anatomical planes of the wrist.
  
  
  METHODS
  In a prospective trial, 34 patients with a suspected scaphoid fracture underwent CT scanning within 10 days after trauma. CT reformations along the long axis of the scaphoid (CT-scaphoid) and along planes relative to the wrist (CT-wrist) were made. We used radiographs obtained 6 weeks after injury as the reference standard for a true fracture. A blinded panel including two surgeons and one radiologist came to a consensus diagnosis for each reformation plane.
  
  
  RESULTS
  The reference standard showed six fractures of the scaphoid (prevalence, 18 %). Using CT-wrist, a scaphoid fracture was diagnosed in five patients (15 %), with three false positive, four false negative and two true positive diagnoses. Using CT-scaphoid, a scaphoid fracture was diagnosed in five patients (15 %), with one false positive, two false negative and four true positive results. Sensitivity, specificity and accuracy were 33, 89 and 79 % for CT-wrist and 67, 96 and 91 % for CT-scaphoid, respectively. This resulted in positive predictive values of 36 % for CT-wrist and 76 % for CT-scaphoid. Negative predictive values were 87 % for CT-wrist and 94 % for CT-scaphoid. No significant differences were found with the number of patients available.
  
  
  CONCLUSIONS
  For diagnosis of true fractures among suspected scaphoid fractures, the diagnostic performance characteristics of CT scans reformatted along the long axis of the scaphoid were better than CT scans in the planes of the wrist, but the differences were not significant.
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Center Amsterdam, Secretariaat Orthopaedie, G4-Noord, Meibergdreef 9, 1100 Amsterdam, The Netherlands.
authors.forename: Wouter H
authors.initials: WH
authors.lastname: Mallee
authors.affiliation: Department of Orthopaedic Surgery, University of Amsterdam Orthopaedic Residency Program, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Job N
authors.initials: JN
authors.lastname: Doornberg
authors.affiliation: Orthopaedic Hand and Upper Extremity Service, Harvard Medical School, Massachusetts General Hospital, Yawkey Center, Suite 2100, 55 Fruit Street, Boston, MA 02114 USA.
authors.forename: David
authors.initials: D
authors.lastname: Ring
authors.affiliation: Department of Radiology, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Mario
authors.initials: M
authors.lastname: Maas
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Maaike
authors.initials: M
authors.lastname: Muhl
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: C Niek
authors.initials: CN
authors.lastname: van Dijk
authors.affiliation: Trauma Unit, Department of Surgery, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: J Carel
authors.initials: JC
authors.lastname: Goslings
keywords: Computed tomography; Diagnostics; Fracture; Reformations; Suspected scaphoid