Mechanical analysis of cartilage graft reinforced with PDS plate

Objectives/hypothesis: This study attempts to characterize the biomechanical properties of a PDS-cartilage composite graft for use in septorhinoplasty.

Study design: Experimental Study.

Methods: This study used a PDS analog, porcine cartilage cut to 1 × 5 × 20 mm, and a mechanical testing platform to measure flexure of a composite graft. Samples were assessed in four groups based on variations in suture pattern and orientation. The platform measured the force required to deflect the sample 2 mm in single cantilever beam geometry before and after the polymer was affixed to the specimen. Elastic Moduli were calculated before and after application of the polydioxanone polymer.

Results: The average modulus of the cartilage alone was 17 ± 0.9 MPa. The modulus of the composite cartilage-polymer graft with 2 suture fixation was 21.2 ± 1.5 MPa. The 3-suture configuration produced an increase to 25.8 ± 2.23 MPa. The four-suture configuration produced 23.1 ± 3.19 MPa. The five-suture configuration produced 25.7 ± 2.6 MPa. The modulus of the analog alone was 170 ± 30 MPa. The modulus of the 0.5 mm PDS was 692 ± 37.4 MPa. The modulus of the 0.15 mm perforated PDS was 447 ± 34.8 MPa.

Conclusions: The study found that suturing a polymer plate to cartilage resulted in enhanced stiffness of the composite. Under the conditions of the study, there was no significant difference in elastic moduli between suture configurations, making the two-suture linear configuration optimal in the one-plane cantilever deflection model.