Biomechanics: Functional Adaptation and Remodeling

313 Pages·1996·9.56 MB·English

by  Masaaki Sato

Springer
Tokyo
Berlin
Heidelberg
New York
Barcelona
Budapest
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London
Milan
Paris
Santa Clara
Singapore
K. Hayashi· A. Kamiya . K. Ono
(Eds.)
Biomechanics
Functional Adaptation
and Remodeling
With 180 Figures
Springer
Kozaburo Hayashi, Ph.D.
Department of Mechanical Engineering, Faculty of Engineering Science, Osaka Univer
sity, 1-3 Machikaneyama-cho, Toyonaka, Osaka, 560 Japan
Akira Karniya, M.D., Ph.D.
Institute of Medical Electronics, University of Tokyo School of Medicine, 7-3-1 Hongo,
Bunkyo-ku, Tokyo, 113 Japan
Keiro Ono, M.D., Ph.D.
Osaka Koseinenkin Hospital, 4-2-78 Fukushima, Fukushima-ku, Osaka, 553 Japan
ISBN 978-4-431-68319-3 ISBN 978-4-431-68317-9 (eBook)
DOl 10.1007/978-4-431-68317-9
Printed on acid-free paper
© Springer-Verlag Tokyo 1996
Softcover reprint of the hardcover I st edition 1996
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Preface
Biomechanics is a relatively new research area that seeks to understand the
mechanics of living systems, and to develop approaches applicable to a wide
variety of fields that include biomedical engineering, medical science, clinical
medicine, applied mechanics, and engineering. For the past quarter-century, this
area has grown rapidly and developed greatly, and is now recognized as one of
the most important and interesting fields in basic science. Owing to such recent
progress, the research project entitled Biomechanics of Structure and Function of
Living Cells, Tissues, and Organs was selected as one of the most important
national research projects in Japan. Between 1992 and 1995 this project was
supported financially in part by a Grant-in-Aid for Scientific Research on Priority
Areas (Biomechanics, Nos. 04237101-04237106) from the Ministry of Education,
Science and Culture, Japan, with Kozaburo Hayashi as the principal investigator,
and Hiroyuki Abe, Keiro Ono, Akira Kamiya, and Hiromasa Ishikawa as the
principal co-investigators.
The project was composed of the following five programs: Mechanical Proper
ties of Living Cells, Tissues, and Organs; Biomechanics of Orthopedic Systems
and Motion Analysis; Biomechanics of the Circulatory System; Computational
Biomechanics; and Functional Adaptation and Remodeling of Biological Tissues
and Organs.
More than 70 biomechanics scientists who are also experts in the fields of
engineering, basic science, medical science, clinical medicine, and dentistry par
ticipated in the project and obtained a great deal of invaluable new information.
The classic doctrine "function dictates structure" is reaffirmed in Wolff's law of
the skeletal system. Whether this doctrine holds true for the cardiovascular
system and connective tissues such as heart muscle, blood vessels, tendons,
ligaments, and intervertebral discs is a central question of biomechanics. The
multidisciplinary approach of our research project has thrown new light on the
key issues of biomechanics. Biologists refer to remodeling as the continuous
renewal of bone in the skeleton, while biomechanists consider remodeling to be
the continuous adaptation of bone structure to its mechanical environment.
Continuous renewal of bone is necessary for maintaining the shape and function
of the skeleton during growth. The process takes place, for example, in the
v
VI Preface
cranium and facial bone where accompanying tissue and organ development
leads the skeletal anlage to modified growth (modeling). Here local influences
such as the mechanical, chemical, and electrical environments alter the growth
pattern and organization of the tissue and thereby produce macroarchitectural
features.
Strain-adaptive bone remodeling is an example of continuous adaptation of
bone structure and is often seen in the healing of fractures in juvenile patients, a
representative case being the spontaneous correction of a broken tubular bone
with angular deformity. The relevant sensor, signal, and activators in bone-mass
regulation in this situation have been partially clarified. Recently, one of our
project team discovered a similar response mechanism in vascular endothelial
cells as a result of fluid shear stress. This opens a new frontier in biomechanics.
Another important question is whether remodeling processes underlie the
regressive changes in mechanical properties often accompanying overuse or ag
ing. As far as the skeletal system is concerned the answer appears to be yes; There
must be an efficient remodeling process induced with advanced bone reduction in
the vertebra, since the load-bearing vertical trabeculae in such vertebrae avoid
resorption but the horizontal ones do not. Ligaments, tendons, and intervertebral
discs lack a vigorous reparative or remodeling capacity after the growth period,
hence, the cumulative effects of microdamage to the matrices of these structures
changes from strengthening in the juvenile to weakening in the adult.
Functional adaptation and remodeling has proved not to be a universal phe
nomenon in living cells or tissues but to depend upon species, age, location, and
loading conditions. The importance of nonlinear relationships should not be
overlooked in mathematical models for studying the relationship between stimu
lus and remodeling.
This book was produced to document the unique and important results ob
tained from the above-mentioned research project, and to offer the most up-to
date information on the phenomena of functional adaptation and optimal
remodeling observed in living organs and components for biomedical engineers,
medical scientists, clinicians, and other biomechanics-related engineers and
scientists.
This publication was supported financially in part by a Grant-in-Aid for Pub
lication of Scientific Research Result (No. 77012) from the Ministry of Educa
tion, Science and Culture, Japan. Finally, we wish express our appreciation to the
editorial and production staff of Springer-Verlag, Tokyo for their cooperation in
producing this book.
Kozaburo Hayashi
Akira Kamiya
Keiro Ono
Contents
Preface......................................................... V
List of Contributors .............................................. IX
Response of Endothelial Cells to Mechanical Stress
Response of Vascular Endothelial Cells to Flow Shear Stress:
Phenomenological Aspect
M. SATO, N. KATAOKA, and N. OHSHIMA.............................. 3
Responses of Vascular Endothelial Cells to Fluid Shear Stress:
Mechanism
A. KAMIYA and J. ANDO .......................................... 29
Functional Adaptation and Optimal Control
of the Heart and Blood Vessels
Responses of the Heart to Mechanical Stress
H. TOMOIKE ..................................................... 59
Residual Stress in the Left Ventricle
H. ABE, S. GOTO, T. KIMURA, H. KUSHIBIKI, and S. ARAI . . . . . . . . . . . . . . . 77
Response of Arterial Wall to Hypertension and Residual Stress
T. MATSUMOTO and K. HAYASHI .................................... 93
Tissue Remodeling and Biomechanical Response
in Orthopedics and Orthodontics
Mechanical Stresses and Bone Formation
J. ODA, J. SAKAMOTO, K. AOYAMA, Y. SUEYOSHI, K. TOMITA,
and T. SAWAGUCHI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
VII
VIII Contents
Fatigue Fracture Mechanism of Cancellous Bone
M. MORITA and T. SASADA ........................................ 141
Residual Stress in Bone Structure: Experimental Observation
and Model Study with Uniform Stress Hypothesis
M. TANAKA and T. ADACHI........................................ 169
Response of Knee Joint Tendons and Ligaments to Mechanical Stress
K. HAYASHI, N. YAMAMOTO, and K. yASUDA ........................... 185
Remodeling of Tendon Autograft in Ligament Reconstruction
K. YASUDA and K. HAyASHI..... ... . .................... .......... 213
Instability of the Spinal System with Focus on Degeneration
of the Intervertebral Disc
S. EBARA, T. HARADA, T. ODA, E. WADA, S. MIYAMOTO, K. YONENOBU,
M. TANAKA, and K. ONO .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 251
Biological Response in Orthodontics
S. NAKAMURA, H. ISHIKAWA, Y. SATOH, T. KANEKO, N. TAKAHASHI,
and M. WAKITA ................................................. 283
Subject Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 307
List of Contributors
Abe, H. 77 Oda, J. 123
Adachi, T. 169 Oda, T. 251
Ando, J. 29 Ohshima, N. 3
Aoyama, K. 123 Ono, K. 251
Arai, S. 77 Sakamoto, J. 123
Ebara, S. 251 Sasada, T. 141
Goto, S. 77 Sato, M. 3
Harada, T. 251 Satoh, Y. 283
Hayashi, K. 93, 185, 213 Sawaguchi, T. 123
Ishikawa, H. 283 Sueyoshi, Y. 123
Kamiya, A. 29 Takahashi, N. 283
Kaneko, T. 283 Tanaka, M. 169, 251
Kataoka, N. 3 Tomita, K. 123
Kimura, T. 77 Tomoike, H. 59
Kushibiki, H. 77 Wada, E. 251
Matsumoto, T. 93 Wakita, M. 283
Miyamoto, S. 251 Yamamoto, N. 185
Morita, M. 141 Yasuda, K. 185, 213
Nakamura, S. 283 Y onenobu, K. 251
IX
Response of Endothelial Cells
to Mechanical Stress
Response of Vascular Endothelial
Cells to Flow Shear Stress:
Phenomenological Aspect
MASAAKI SAT01, NORIYUKI KATAOKAt, and NORIO OHSHIMA2
Summary. Blood vessel walls are covered by an endothelial cell monolayer that
is always exposed to blood flow. A fluid-imposed shear stress acting on endothe
lial cells is defined as a tangential force produced by blood viscosity and a velocity
gradient. There are many reports that endothelial cells respond to shear stress
and change their morphology and functions. Blood flow characteristics have
received special attention because atherogenesis is found around arterial
branches and curved regions. In this chapter the effects of fluid-imposed shear
stress on endothelial cell morphology, which have been reported by ourselves
and other researchers, are mainly summarized. We also focused on flow patterns
such as reverse, secondary, pulsatile, and turbulent flows. This kind of complex
flow would occur in the in vivo condition, especially around arterial bifurcations
and curved sites, and would certainly affect cell morphology. From the impor
tance of adhesive proteins in the role of connecting endothelial cells and
subendothelial structures, we inferred the effects of extracellular matrices and
cytoskeletal components on cell morphology from the changes in endothelial cell
shape and actin filament structure. Because the cytoskeletal changes of endothe
lial cells after exposure to shear stress are closely correlated with mechanical
properties, we applied a micropipette technique to examine stiffness and vis
coelastic properties.
Key words: Atherosclerosis-Endothelial cell-Extracellular matrix-Shear
stress-Mechanical property
Biomechanics Laboratory, Graduate School of Mechanical Engineering, Tohoku Uni
1
versity, Aoba, Aramaki, Aoba-ku, Sendai, 980-77 Japan
Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, 305 Japan
2
3