Cadaveric and engineering analysis of the septal L-strut.
OBJECTIVE
To identify patterns of failure of the L-strut, to identify elements of the nasal framework that support the L-strut, and to investigate the effect of altering L-strut design on its stability.


METHODS
Laboratory study with human cadaveric heads and computational modeling.


METHODS
Directional forces were applied to cadaveric L-struts and patterns of failure with incremental force were noted. Computational modeling using the finite element method (FEM) was employed to determine quantitatively the effect of various modifications on the stability of the L-strut.


RESULTS
The L-strut was found to respond to frontal force initially by buckling. This buckling was reversible until the force exceeded a certain threshold when the L-strut broke at the bony-cartilaginous junction. The threshold force varied depending on the length of the overlap with the bony vault. Intact mucoperichondrium provided significant stability. Modeling with FEM showed that the preservation of a triangular piece of cartilage at the dorsal anchor of a narrowed L-strut can offset some of the loss in mechanical stability.


CONCLUSIONS
Intrinsic elasticity of the septal cartilage, the mucoperichondrial flap, and overlap with the bony vault all contribute to the stability of the L-strut, which is enhanced by preserving a small segment of cartilage at the bony-cartilaginous junction of the dorsal L-strut.
Mau
Ted
T
Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, CA, USA.
Mau
Sheng-Taur
ST
Kim
David W
DW
D001696:Biomechanical Phenomena; D002102:Cadaver; D020342:Finite Element Analysis; D006801:Humans; D009300:Nasal Septum / Q000601:surgery*; D012225:Rhinoplasty / Q000379:methods*; D013718:Tensile Strength; D017211:Treatment Failure