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Optimum Topology and Shape Design of an Interbody Fusion Implant for Lumbar Spine Fixation Andrés Tovar, John E. Renaud and James J. Mason. University of Notre Dame Department of Aerospace and Mechanical Engineering
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Optimum Topology and Shape Design of an Interbody Fusion Implant for Lumbar Spine FixationAndrés Tovar, John E. Renaud and James J. Mason University of Notre DameDepartment of Aerospace and Mechanical Engineering Eight International Conference on Computer Aided Optimum Design of Structures - OPTI2003May 19 - 21, 2003 OPTI2003 - Design of an Interbody Fusion Implant
Content • The Spinal Column • Phase 1 – Topology Optimization • Phase 2 – Shape Optimization • Results, Summary and Conclusions OPTI2003 - Design of an Interbody Fusion Implant
The Spinal Column OPTI2003 - Design of an Interbody Fusion Implant
The Spinal ColumnDisc problems [Spineuniverse] OPTI2003 - Design of an Interbody Fusion Implant
The Spinal ColumnSome facts [Katz, 1995] OPTI2003 - Design of an Interbody Fusion Implant
The Spinal ColumnFusion with instrumentation PLIF – Posterior Lumbar Interbody Fusion [Virginia Spine Institute] OPTI2003 - Design of an Interbody Fusion Implant
The Spinal ColumnInterbody cage fusion ALIF – Anterior Lumbar Interbody Fusion [Spineuniverse] OPTI2003 - Design of an Interbody Fusion Implant
The Spinal ColumnNew fusion procedure Vertebra Implant Implant Bond Graft OPTI2003 - Design of an Interbody Fusion Implant
Topology Optimization [Belegundu, 1999] OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationDesign domain 2064 design variables [FEBM / GENESIS] OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationVertebra model Cancellous bone Cortical bone Design domain Cartilage [Goel and Weinstein, 2000] OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationLoad conditions • Flexion 15.0 Nm • Extension 5.0 Nm • Lateral bending 7.5 Nm [Rohlmann et al, 2001] OPTI2003 - Design of an Interbody Fusion Implant
Topology Optimization Lateral bending Left & right lateral bending 7.5 Nm + + OPTI2003 - Design of an Interbody Fusion Implant
Topology Optimization Flexion and extension Flexion 15.0 Nm Extension 5.0 Nm + + OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationThe optimization problem [Bendsøe & Sigmund, 1999] OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationThe optimization problem OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationOptimum topologies OPTI2003 - Design of an Interbody Fusion Implant
Topology OptimizationSpline approximation OPTI2003 - Design of an Interbody Fusion Implant
Shape Optimization [GENESIS] OPTI2003 - Design of an Interbody Fusion Implant
Shape OptimizationDomains and perturbation vectors 18 domains 18 design variables 444 elements OPTI2003 - Design of an Interbody Fusion Implant
Shape OptimizationThe optimization problem OPTI2003 - Design of an Interbody Fusion Implant
Shape OptimizationOptimum shape Initial shape Optimum shape OPTI2003 - Design of an Interbody Fusion Implant
Results Designs Stress analysis OPTI2003 - Design of an Interbody Fusion Implant
Summary and Conclusions • An optimum geometry for a new interbody fusion implant is obtained using topology and shape optimization. • The topology optimization minimize strain energy subject to a mass fraction constraint for 2064 design variables. • The shape optimization minimize mass subject to a maximum von Mises stress constraint for 18 design variables. • A total volume fraction of 60% (respect to the original design volume) is available for the bone graft. OPTI2003 - Design of an Interbody Fusion Implant