Sternal plating for primary and secondary sternal closure; can it improve sternal stability?
BACKGROUND
Sternal instability with mediastinitis is a very serious complication after median sternotomy. Biomechanical studies have suggested superiority of rigid plate fixation over wire cerclage for sternal fixation. This study tests the hypothesis that sternal closure stability can be improved by adding plate fixation in a human cadaver model.


METHODS
Midline sternotomy was performed in 18 human cadavers. Four sternal closure techniques were tested: (1) approximation with six interrupted steel wires; (2) approximation with six interrupted cables; (3) closure 1 (wires) or 2 (cables) reinforced with a transverse sternal plate at the sixth rib; (4) Closure using 4 sternal plates alone. Intrathoracic pressure was increased in all techniques while sternal separation was measured by three pairs of sonomicrometry crystals fixed at the upper, middle and lower parts of the sternum until 2.0 mm separation was detected. Differences in displacement pressures were analyzed using repeated measures ANOVA and Regression Coefficients.


RESULTS
Intrathoracic pressure required to cause 2.0 mm separation increased significantly from 183.3 +/- 123.9 to 301.4 +/- 204.5 in wires/cables alone vs. wires/cables plus one plate respectively, and to 355.0 +/- 210.4 in the 4 plates group (p < 0.05). Regression Coefficients (95% CI) were 120 (47-194) and 142 (66-219) respectively for the plate groups.


CONCLUSIONS
Transverse sternal plating with 1 or 4 plates significantly improves sternal stability closure in human cadaver model. Adding a single sternal plate to primary closure improves the strength of sternal closure with traditional wiring potentially reducing the risk of sternal dehiscence and could be considered in high risk patients.
Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Terrence Donnelly Heart Center, Keenan Research Center in the Li Ka Shing Knowledge Institute of St Michael's Hospital, University of Toronto, Ontario, Canada. hosamfawzy@hotmail.com
Hosam
H
Fawzy
Nasser
N
Alhodaib
C David
CD
Mazer
Alana
A
Harrington
David
D
Latter
Daniel
D
Bonneau
Lee
L
Errett
James
J
Mahoney
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001860:Bone Plates; D001864:Bone Wires; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D012044:Regression Analysis; D013249:Sternum / Q000601:surgery*; D013536:Suture Techniques; D013908:Thoracotomy / Q000379:methods