title: Concentric and eccentric carved costal cartilage: a comparison of warping.
abstract: OBJECTIVE
  To determine if a systematic, concentric graft-carving technique results in less warping than eccentric carving.
  
  
  METHODS
  Costal cartilage from ribs 3 through 9 were harvested from fresh human cadavers. Concentric dorsal grafts were carved from cartilage obtained from one side of the cadaver (n = 7) and eccentric grafts were carved from the opposite side (n = 11). After carving, grafts were placed in saline sponges (isotonic sodium chloride) for 1 hour, and photographs were then taken from a lateral and a frontal view. Identical photographs were taken after 2 weeks of incubation in saline (36.7 degrees C). The angle of curvature was measured from the photographs.
  
  
  RESULTS
  More warping occurred in the eccentric group than the concentric group on lateral view at 1 hour (4.4 degrees vs 0.4 degrees; P<.001) and at 2 weeks (5.8 degrees vs 1.4 degrees; P = .003). Eccentric grafts progressively warped between the 1-hour and 2-week points.
  
  
  CONCLUSIONS
  Meticulous concentric carving of costal cartilage grafts may minimize the complication of graft warping.
authors.affiliation: Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, 94115, USA. dkim@ohns.ucsf.edu
authors.forename: David W
authors.initials: DW
authors.lastname: Kim
authors.forename: Anil R
authors.initials: AR
authors.lastname: Shah
authors.forename: Dean M
authors.initials: DM
authors.lastname: Toriumi
mesh_terms: D002102:Cadaver; D002356:Cartilage / Q000637:transplantation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012225:Rhinoplasty / Q000379:methods*; D012272:Ribs / Q000601:surgery*; D018709:Statistics, Nonparametric