title: Biomechanical comparison of median sternotomy closures.
abstract: BACKGROUND
  Poor healing of median sternotomy can significantly increase morbidity, mortality, and hospital costs. Effective union requires reliable sternal fixation. Although wire has proven the most reliable and widely used sternotomy closure material, no experimental studies have compared a large variety of wiring techniques in a human model. We developed an easily reproducible experimental model using cadaveric human sterna and compared several wiring methods to assess closure strength and stability.
  
  
  METHODS
  Fifty-three fresh adult human cadaveric sternal plates with adjacent ribs were fixed with specially designed spiked stainless steel clamps and attached to a texture analyzer. Single peristernal and transsternal, alternating single peristernal and transsternal, figure-eight peristernal, figure-eight pericostal, and Robicsek closures using no. 5 stainless steel wires were tested. We evaluated bone density, stiffness, and displacement using perpendicular, repetitive variable force loads of 800 Newtons cycling at a rate of 0.5 mm/s.
  
  
  RESULTS
  There were no significant differences in age, sex, or bone density in outcome measures of the sternal groups. No clamp failures or clamp damage to the specimens occurred. The single peristernal and alternating peristernal and transsternal closures proved superior in strength and stability (p < 0.001). The figure-eight peristernal, then the single transsternal, then the Robicsek were next stablest groups in decreasing order. The figure-eight pericostal closure had the highest failure rate (p < 0.001).
  
  
  CONCLUSIONS
  This novel model of sternotomy closure testing was reliable, inexpensive, and easily reproducible. The mechanical stability of peristernal and alternating peristernal and transsternal wires was significantly greater than that of the other tested methods. Pericostal figure-eight closures were not sufficiently stable to be considered a reliable method of primary sternotomy repair.
authors.affiliation: Department of Surgery, University of Missouri-Columbia, Columbia, Missouri 65212, USA.
authors.forename: Julian E
authors.initials: JE
authors.lastname: Losanoff
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Collier
authors.forename: Colette C
authors.initials: CC
authors.lastname: Wagner-Mann
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Richman
authors.forename: Harold
authors.initials: H
authors.lastname: Huff
authors.forename: Fu hung
authors.initials: Fh
authors.lastname: Hsieh
authors.forename: Alberto
authors.initials: A
authors.lastname: Diaz-Arias
authors.forename: James W
authors.initials: JW
authors.lastname: Jones
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena / Q000295:instrumentation; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013249:Sternum / Q000502:physiology* / Q000601:surgery*; D019616:Thoracic Surgical Procedures / Q000379:methods