D148. Evaluation of Mechanical Strength of 3D-Printed L-Strut Implants in Septal Reconstruction Using Finite Element Analysis

PURPOSE: Autologous nasoseptal cartilage grafts can correct nasal asymmetry and deviation in rhinoplasty, but patients with severe deformations often have limited autologous septal cartilage available. 3D-printed L-strut implants may address these challenges in the future, but their mechanical strength is understudied. Silk fibroin-gelatin (SFG), polycaprolactone (PCL), and polylactide (PLA) are bioinks known for their strength. We present Finite Element Analysis (FEA) models comparing the mechanical strength of 3D-printed SFG, PCL, and PLA implants with nasoseptal cartilage grafts when autologous or allografts are not able to be used. METHODS: FEA models compared the stress and deformation responses of 3D-printed solid and scaffold implant replacements to cartilage. A daily physiological load simulated force from overlying soft tissue was applied at the "keystone" region given its structural role and compared with native cartilaginous properties. RESULTS: 3D-printed solid SFG, PCL, and PLA and scaffold PCL and PLA models demonstrated lower deformations compared to cartilage. Solid SFG balanced strength and flexibility. The maximum stress was below all materials' yield stresses suggesting their deformations are unlikely permanent under a daily load. CONCLUSION: Our FEA models suggest that 3D-printed L-strut implants carry promising mechanical strength. Solid SFG's results mimicked cartilage's mechanical behavior. Thus, scaffold SFG merits further optimization for potential use as cartilage replacement. 3D-printed septal cartilage replacement implants potentially enhances surgical management of patients with severe septal deformations in select settings.