ADDITIVE MANUFACTURING FOR BONE LOAD BEARING APPLICATIONS - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 224

CHAPTER

11

ADDITIVE MANUFACTURING
FOR BONE LOAD BEARING
APPLICATIONS

Mihaela Vlasea 1 , Ahmad Basalah 1 , Amir Azhari 1 , Rita Kandel 2 and Ehsan Toyserkani 1
1 Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON, Canada
2 Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada

11.1 NEED FOR BONE SUBSTITUTES
The incentive behind fabricating constructs with a direct application in bone and joint reconstruc-
tion surgeries lies in understanding the demand for such devices. Bone and cartilage conditions, such
as arthritis, osteoporosis, traumatic musculoskeletal injuries, spinal injuries, and spinal deformities
( Hutchinson, 2009 ), although mostly nonlife-threatening, can become very incapacitating, diminishing
the quality of life of the affected individuals by causing ongoing pain, discomfort, inflammation, and
restrictions in range of motion ( Hutchinson, 2009 ). Furthermore, these conditions represent a major
financial burden on the healthcare sector ( Hutchinson, 2009; Cheng et al., 2013 ). The current conven-
tional treatment for advanced joint and bone trauma is to fully or partially replace the affected area with
tissue grafts ( Gikas et al. , 2009 ) or with artificial prosthetics ( Bartel et al., 2006 ) to restore near-normal
functions. Current state-of-the-art prosthetic implants fail to meet structural and functional require-
ments that would render them as permanent remediation solutions ( Bartel et al., 2006 ). As a result,
thousands of patients undergo painful and costly subsequent surgeries for implant replacements or
readjustments. Cell-based or tissue graft solutions have been proven to ameliorate the quality of life of
patients, but are limited in terms of size and anatomical shape of defect that can be addressed, as well as
the availability of healthy donor tissue and morbidity of the donor site ( Koh, 2004 ; Gikas et al., 2009 ;
Vasiliadis et al., 2010 ). There is a pressing need for more successful bone and osteochondral reconstruc-
tion approaches that take into account biochemical, morphological, and anatomical factors. One such
approach focuses on manufacturing biocompatible and/or bioresorbable bone substitutes with complex
internal and external architecture and appropriate biochemical cues that can enhance or replace the
defect area, gradually mature, and seamlessly integrate with the native tissue ( Hutmacher, 2000 ). The
bone substitute would serve as a biocompatible template that would encourage cell migration, prolif-
eration, and differentiation, ideally acting as a temporary bioresorbable porous support until the bone
matrix is regenerated ( Bohner et al., 2011 ). A vast amount of work has been done in materials research
and manufacturing methodologies in this field, specifically in constructing bone substitutes for load
bearing applications; however, there is still a gap in understanding the ideal relationship between the