203 posters, 14 topics, 5 sessions, 817 authors, 256 institutions
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The AAPS 102nd Annual Meeting
May 18-21, 2024 | The Westin Copley Place, Boston, MA
D148
Evaluation Of Mechanical Strength Of 3D-Printed L-Strut Implants In Septal Reconstruction Using Finite Element Analysis
Poster Presenter
Authors
Iulianna Taritsa, Sujata Syamal, Angelica Hernandez Alvarez, Kirsten Schuster, Jose Foppiani, David Kaplan, Samuel Lin
Affiliations
Division of Plastic and Reconstructive Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Harvard University Extension School, Cambridge MA, Department of Biomedical Engineering, Tufts University, Medford, MA
Part of Topic
Basic Science Research
Evaluation Of Mechanical Strength Of 3D-Printed L-Strut Implants In Septal Reconstruction Using Finite Element Analysis
Background
•Autologous nasoseptal cartilage grafts can correct nasal asymmetry and deviation in rhinoplasty
•When there is limited autologous septal cartilage available (e.g., severe nasal deformations), options for reconstruction are limited and carry drawbacks
•3D-printed L-strut implants may provide a solution but their mechanical strength is understudied
•Silk fibroin-gelatin (SFG), polycaprolactone (PCL), and polylactide (PLA) are bioinks with potential to be used in nasoseptal constructs
•Computational simulations can evaluate 3D-printed implant strength and their potential to replace septal cartilage in septorhinoplasty.
Purpose
•We present Finite Element Analysis (FEA) models comparing the mechanical strength of 3D-printed SFG, PCL, and PLA implants with nasoseptal cartilage grafts
•We tested each material strategically at the “keystone” region, a critical location of nasal dorsum support
•Keystone region represents where the perpendicular plate of the ethmoid bone, septal cartilage, nasal bones, and lateral nasal cartilages meet
Methods
GEOMETRY
•Single layer, uniform solid body L-strut CAD model was created using ANSYS
•Dorsal limb width: 10mm; Caudal limb width: 15 mm
•To mimic nasal cartilage mechanical behavior, scaffold models had:
•50% porosity
•116 µm pore size
•90° lay-down angle between layers
•Regular cubic lattice design with cylindrical fibers.
MATERIAL PROPERTIES
•All materials assumed to observe isotropic behavior
•All materials were modeled assuming linear elastic behavior
FEA MODEL
•FEA was performed using ANSYS Mechanical
•Hexahedral mesh for solid and scaffold models
•The boundary conditions included fixed supports at the proximal faces of the dorsal and caudal limbs simulating fixation to the PPE and maxillary crest respectively
•A 0.01 N unidirectional load was applied at 9 mm from the proximal edge of the dorsal limb simulating the skin and subcutaneous tissue exerting a daily force at the average “keystone” region
Results
•PLA exhibits the least deformation when compared with both the standard of care of nasal septal cartilage and 3D printed solid PCL and SFG implant materials.
•All solid models and scaffold PCL and PLA experienced lower deformation than the nasal septal cartilage
•Among solid models, PLA is the stiffest and septal cartilage is most flexible as expected
•All scaffold models had higher deformations than their solid model counterparts with PLA being the stiffest and SFG is most flexible.
•All maximum von-Mises stress results are well below any individual material’s yield stress signifying potential to withstand a single daily physiological force without permanent deformation.
Discussion & Implications in PRS
•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.
•Our FEA models suggest that 3D-printed L-strut implants carry promising mechanical strength.
•Solid SFG’s results mimicked cartilage’s mechanical behavior.
•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.