Modeling and Numerical Analysis of a Cervical Spine Unit - Biologically Responsive Biomaterials for Tissue Engineering - page 136

Chapter 7
Modeling and Numerical Analysis of a Cervical
Spine Unit

Mirela Toth-Tascau and Dan Ioan Stoia

7.1 Introduction

Pathological or accidental disorders of the human spine are responsible for wors-
ening the living conditions of over 5 % of world population, and for some of
them, the only way to reduce pain is surgical implantation. Surgery can heal or
improve initial findings and may also alleviate, or even completely eliminate, the
existing pain and dysfunctions. The continuing trends of life quality improve-
ment in modern society play a key role in spinal implant development. In patients
with spinal implants, the performances and sustainability of mechanical systems
help in reducing the pain.
Decade of the Spine was initiated to promote awareness of the spine, spine care,
and spine research. Over the course of the decade, this major spine initiative met its
mission “to improve the quality of spinal care worldwide” [ 4 ] .
The movement possibilities and the functionality of the spine are provided by its
structural complexity. The spinal column (or vertebral column) extends from the
skull to the pelvis and it counts 33 individual bones termed vertebrae. The vertebrae
are stacked on top of each other and grouped into four regions: cervical, thoracic,
lumbar, and sacral. In addition to the 33 vertebrae, the spine involves 24 interverte-
bral discs, 344 joint facets, 356 ligaments, 730 direct action muscles, and 730 points
of insertion [ 41 ]. The 31 pairs of spinal nerves and the vascular system have to be
added as well. Such a complex mobile system leads to a very complex mechanical
behavior.
Bone is a living tissue exquisitely adapted to resist stress with suitable resilience,
which supports the body and provides leverage for movements. At the macroscopic
level the bone has two structure components: compact or cortical bone and cancel-
lous, trabecular, or spongy bone [ 47 ]. Compact bone can be considered as a solid,

M. Toth-Tascau ( * ) • D. I. Stoia
Politehnica University of Timisoara , Bd. Mihai Viteazu, No. 1 , Timisoara 300222 , Romania
e-mail: [e-mail] ; [e-mail]