title: Measurement of Clavicle Fracture Shortening Using Computed Tomography and Chest Radiography.
abstract: BACKGROUND
  Nonoperative management of midshaft clavicle fractures has resulted in widely disparate outcomes and there is growing evidence that clavicle shortening poses the risk of unsatisfactory functional outcomes due to shoulder weakness and nonunion. Unfortunately, the literature does not clearly demonstrate the superiority of one particular method for measuring clavicle shortening. The purpose of this study was to compare the accuracy of clavicle shortening measurements based on plain radiographs with those based on computed tomography (CT) reconstructed images of the clavicle.
  
  
  METHODS
  A total of 51 patients with midshaft clavicle fractures who underwent both a chest CT scan and standardized anteroposterior chest radiography on the day of admission were included in this study. Both an orthopedic surgeon and a musculoskeletal radiologist measured clavicle shortening for all included patients. We then determined the accuracy and intraclass correlation coefficients for the imaging modalities. Bland-Altman plots were created to analyze agreement between the modalities and a paired t-test was used to determine any significant difference between measurements.
  
  
  RESULTS
  For injured clavicles, radiographic measurements significantly overestimated the clavicular length by a mean of 8.2 mm (standard deviation [SD], ± 10.2; confidence interval [CI], 95%) compared to CT-based measurements (p< 0.001). The intraclass correlation was 0.96 for both plain radiograph- and CT-based measurements (p= 0.17).
  
  
  CONCLUSIONS
  We found that plain radiograph-based measurements of midshaft clavicle shortening are precise, but inaccurate. When clavicle shortening is considered in the decision to pursue operative management, we do not recommend the use of plain radiograph-based measurements.
authors.affiliation: Department of Orthopaedic Surgery, Keck Medical Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Omid
authors.affiliation: Department of Orthopaedic Surgery, Keck Medical Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Kidd
authors.affiliation: Department of Orthopaedic Surgery, University of Washington School of Medicine, Seattle, WA, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Yi
authors.affiliation: Department of Orthopaedic Surgery, Keck Medical Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Villacis
authors.affiliation: Department of Radiology, Keck Medical Center, University of Southern California, Los Angeles, CA, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: White
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002968:Clavicle / Q000000981:diagnostic imaging / Q000293:injuries; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D013902:Radiography, Thoracic / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Fracture; X-ray computed tomography; X-ray film