Analysis of Cartilage-Polydioxanone Foil Composite Grafts

Abstract

This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts.

Keywords

facial plastic surgery - polydioxanone - cartilage - elastic modulus - rhinoplasty

• References

• 1 Boenisch M, Mink A. Clinical and histological results of septoplasty with a resorbable implant. Arch Otolaryngol Head Neck Surg 2000; 126 (11) 1373-1377
• 2 Gomulinski L. The severely deviated septum—the way I solve the problem. Facial Plast Surg 2006; 22 (4) 240-248
• 3 Boenisch M, Nolst Trenité GJ. Reconstruction of the nasal septum using polydioxanone plate. Arch Facial Plast Surg 2010; 12 (1) 4-10
• 4 Conderman C, Kinzinger M, Manuel C, Protsenko D, Wong BJF. Mechanical analysis of cartilage graft reinforced with PDS plate. Laryngoscope 2013; 123 (2) 339-343
• 5 Chao KK, Ho KH, Wong BJ. Measurement of the elastic modulus of rabbit nasal septal cartilage during Nd:YAG (lambda = 1.32 microm) laser irradiation. Lasers Surg Med 2003; 32 (5) 377-383
• 6 Gaon MD, Ho KH, Wong BJ. Measurement of the elastic modulus of porcine septal cartilage specimens following Nd: YAG laser treatment. Lasers Med Sci 2003; 18 (3) 148-153
• 7 Hibbeler RC. Mechanics of Materials. . 7th ed. Upper Saddle River, N: Pearson Prentice Hall; 2008: 333-351
• 8 Tweedie DJ, Lo S, Rowe-Jones JM. Reconstruction of the nasal septum using perforated and unperforated polydioxanone foil. Arch Facial Plast Surg 2010; 12 (2) 106-113