Abstract

Porous metals are found to be suitable as orthopedic scaffolds. However, only limited control over the internal architecture can be achieved using conventional design methods. The architecture with porosity variation strategy mimicking natural bone is critical to gain favorable combination of mechanical and biological properties for orthopedic implants. In this regard, a topology optimization method with customized morphology and mechanical properties derived from the trabecular bone was proposed to design three-dimensional architectures with gradient porosity resembling the porous structure of bone. In particular, the elastic constants for the trabecular bone were better predicted when the bone volume fraction was supplemented with a three-dimensional structural parameter, i.e., degree of anisotropy. These constants were set as the optimization constrains for morphology control. Then the porous titanium structures were manufactured by selective laser melting technology (SLM). The physical characteristics, mechanical properties of the scaffolds were compared systematically. The experimental results revealed that the as-built samples with the proposed method lead to a good match of morphological accuracy and mechanical properties to that of the bone. It demonstrates that the proposed topology optimization method with controlled morphology and mechanical properties provides an efficient manner for the biomimetic design of orthopedic implants.

Highlights

  • Skeletal reconstruction of bone defects for load-bearing application is still a major challenge in orthopedic surgery

  • This table indicates that both the bone volume (BV)/total volume (TV) and trabecular number gradually decreases from L1 to L5

  • After analyzing the correlation between morphology para-meters and mechanical properties, BV/TV and degree of orientation (DA) were identified to be highly related to the structural design

Read more

Summary

Introduction

Skeletal reconstruction of bone defects for load-bearing application is still a major challenge in orthopedic surgery. To satisfy the biomechanics requirement of orthopedic scaffolds, a porous structure mimicking natural bone should be taken into consideration. Current mainstream direction is to design uniform porous structure constructed by periodically repeating unit cells along all directions [3]. Various topological designs of porous structures by controlling the porosity of implants have been reported [4]. Parameters such as porosity, pore size and pore interconnectivity have been carefully selected. The specific selection range of these structural features is still controversial. Conventional regular porous implant design techniques neglect the isotropic pressure micro-environment of the trabecular bone growth and cannot fulfill the biomechanical demands [5].

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call