title: Dimensions of the trapezium bone: a cadaver and CT study.
abstract: OBJECTIVE
  The primary purpose of this study was to define the size of the trapezium bone through measurements on cadaver specimens and CT scans of living subjects. The secondary purpose of this study was to determine if any correlation existed between the size of the trapezium and local anatomical parameters.
  
  
  METHODS
  The radio-ulnar length (L), dorsopalmar width (ℓ) and height (h) of the distal surface of the trapezium were measured by two independent observers on 20 cadaver specimens. The same measurements were carried out by two other observers on anonymized CT scans from 18 patients. The inter- and intra-observer agreement was determined using the intraclass correlation coefficient.
  
  
  RESULTS
  In the cadavers, the mean length, width and height of the trapezium were 22.8, 15.5 and 15.2 mm, respectively. On the CT scans, these same dimensions were 19.2, 11.4 and 11.6 mm. Inter-observer agreement was statistically significant in both parts of the study.
  
  
  CONCLUSIONS
  The dimensions of the trapezium bone were about 3.33 mm larger in cadavers than on CT scans. These differences can be explained partially by a systematic under-sizing error on the CT scans and the fact that the cartilage layer cannot be directly visualized.
  
  
  CONCLUSIONS
  This study was able to define the dimensions of the trapezium bone. It may be possible to predict the trapezium height from the length of the forearm or the width of the radial epiphysis. Our data can be used to adjust the size of trapezium implants to the dimensions of the patient's bone.
authors.affiliation: Laboratoire d'Anatomie, UFR SMP, 20 rue Ambroise Paré, Besançon, France, francois_loisel@yahoo.fr.
authors.forename: F
authors.initials: F
authors.lastname: Loisel
authors.forename: S
authors.initials: S
authors.lastname: Chapuy
authors.forename: P-B
authors.initials: PB
authors.lastname: Rey
authors.forename: L
authors.initials: L
authors.lastname: Obert
authors.forename: B
authors.initials: B
authors.lastname: Parratte
authors.forename: L
authors.initials: L
authors.lastname: Tatu
authors.forename: D
authors.initials: D
authors.lastname: Lepage
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051222:Trapezium Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*