Post on 18-Oct-2020
Advances in Biomaterials, 8
Implant Materials in Biofimction Proceedings of the Seventh European Conference on Biomaterials, Amsterdam, The Netherlands, September 8 -11 ,1987
edited by
C . de Putter 1 , G.L. de Lange 2 , Κ. de Groot 3
1 Department of Oral Implantology, 2 Department of Oral Biology, 3 Department of Biomaterials, Academic Centre for Dentistry Amsterdam (ACTA), Free University, Amsterdam, The Netherlands
and
A.J.C. Lee Department of Engineering Science, University of Exeter, Exeter, England
E L S E V I E R Amsterdam — Oxford — New York — Tokyo 1988
IX
Contents
Series Foreword V
Preface VII
Keynote lectures
Regulation in the field of biomaterials in the Federal Republic of Germany E. Tschöpe 1
Consensus and definitions in biomaterials D.F.Williams 11
Biomechanical requirements on ligament prostheses L. Claes, L. Dürselen , 17
Section 1. Biocompatibility testing »
Biocompatibility of Estane® and PBT/HPOE (45/55) segmented polyether polyester copolymer during infection D. Bakker, C.A. van Blitterswijk, S.C. Hesseling, W. Th. Daems, J J . Grote 25
Surface modification of synthetic polymer materials for medical use: addition of fibrinolytic and antibacterial activities S. Watanabe, O. Ike, T. Nakamura, Y. Shimizu, Y. Tamada, Y. Ikada 31
Leukocytes at the tissue-implant interface L.M. Bjursten, A.S. Eriksson, R. Olsson, P. Thomsen, L.E. Ericson 37
Accumulation of trace elements by macrophages during degradation of biomaterials. An electron microscopical and X-ray microanalytical study H.K. Koerten, C.A. van Blitterswijk, J.J. Grote, W.Th. Daems 43
Biomaterial/tissue interface characteristics of four elastomers D. Bakker, C.A. van Blitterswijk, S.C. Hesseling, W.Th. Daems, J.J. Grote 49
Quantitative in vitro measurements of three cellular properties involved at tissue/material interface. Standardisation of the technique M.F. Sigot-Luizard, J.L. Duval, M. Letort, M. Sigot 55
Reconstruction of the abdominal wall with processed sheep dermal collagen — an experimental study in dogs A.C. van der Wal, N.J.Μ. Out, Α. van den Hooff, P.J. Klopper 61
Section 2. Biomaterial-hard tissue interactions
Histologie reactions to different hydroxyapatite granules S. Jänicke, W. Wagner, U. Wahlmänn 67
Collagenous and non-collagenous bone proteins in rats and rabbits at the bone-implant interface of bone-bonding and non-bonding glass-ceramics R. W. Kinne, H.-J. Schmitz, U. Gross 73
Tissue response to a bioactive glass-metal interface E. Schepers, Μ. De Clercq, P. Ducheyne 79
Removal forces for osseointegrated titanium implants C. Johansson, M. Jacobsson, T. Albrektsson 87
Reconstruction of the external ear canal and middle ear with hydroxyapatite implants H.W. Lutgert, C.A. van Blitterswijk, J.J. Grote 93
Morphometric and histologic evaluation of enosseal implanted carbon fibre reinforced polysulfone U.W. Wahlmann, W. Wagner 99
Relation between physico-chemical solubility and biodegradability of calcium phosphates F. C.M. Driessens, R.M.H. Verbeeck 105
χ
Section 3. Orthopaedics
A new design of ligament prosthesis for anterior cruciate ligament replacement J. Leandri, Ph. Dahhan, 0. Tarragano, M. Cerol, P. Rev, D. Geiger 113
Aramid fibers and bone interactions in anterior cruciate ligament repair in dogs N. Passuti, G. Daculsi, M. Vigneron, J.C. Le Nihouannen, C. Cistac 119
Material properties of human cruciate ligaments in total knee arthroplasty Th. Mittlmeier, G. Wasmer, G.O. Hofmann, F.-W. Hagena, M. Bergmann, A. Walter 125
Experimental biomechanics of the femoropatellar joint after implantation of different knee joint endoprostheses G.O. Hofmann, F.-W. Hagena, J.S. Zimmermann 131
Pathomechanical aspects of failed total knee arthroplasties F. -W. Hagena, G.O. Hofmann, J.S. Zimmermann 137
On the geometrical shape of artificial hip joint bearings with articulation of identical materials A. Walter, F. Böhmer 143
Influence of assemblage geometry and fracture type on stability of monolateral external fixation B. Dreithaler, H.H. Schauwecker, Μ. Schmargon, R. Wilk 149
Ceramic prosthesis in reintervention for "aseptic" loosening G. Gualtieri, I. Gualtieri, S. Gagliardi, M. Hendriks 155
Porous polysulfone coated femoral stems A.J. Gavens, N.B. Beals, M.F. DeMane, J.A. Davidson, J.R. Roberson, I. Heyligers, M. Miller, M. Spector 159
Bioglaze coating of metallic femoral prosthetic stems: fatigue test A. Moroni, R. Mongiorgi, M. Marcacci, A. Krajewski, A. Ravaglioli 165
Investigation of the neo-synovia at knee prostheses A. Walter, F.-W. Hagena, G.-O. Hofmann 171
The clinical use of plastic plates for osteosynthesis in human fractures A.J. Tonino 177
Section 4. Biomaterials and complement activation
Molecular mechanism of complement activation on polymer surfaces: contact activation of reconstituted first component (C1) of classical pathway M. Niinobe, T. Matsuda, H. Twata 181
Effects of the hydrophobic-hydrophilic nature of the polymer surfaces on the complement activation S. Yoshikawa, H. Fukumura, Y. Akagaki, S.-Y. Inai 187
Comparative study of proteins adsorbed on dialysis membranes, complement and platelets activation V. Panichi, A.M. Bianchi, L. Casarosa, R. Cominotto, M. Parrini, G. Grazi, C. Cirami, R. Palla 193
New polymethylmethacrylate-polyurethane (PMMA-PU) membranes for hemodialysis applications G. Soldani, M. Palla, G. Barini, P. Giusti, G. Levita, A.M. Bianchi, V. Panichi, R. Palla 201
Section 5. Biological performance of Ca-phosphates
In vitro interactions between calcium phosphate biomaterials and human fibroblastic cell. I. Comparative extra and intracellular evolution of 4 synthetic calcium phosphates I. Orly, M. Gregoire, J. Menanteau, I. Jans, J.C. Heughebaert, B. Kerebel 211
In vitro interactions between calcium phosphate biomaterials and human fibroblastic cell. II. Incidences on the behavior of cultured gingival cells M. Gregoire, I. Orly, J. Menanteau, M. Heughebaert, B. Kerebel 215
XI
Biological performance of hydroxyapatite as otologic biomaterial: An evaluation of clinical applied hydroxyapatite C.A. van Blitterswijk, J.J. Grote, H.W. Lutgert, H.K. Koerten 221
Histologic evaluation of ceramo-osseous regeneration complexes in human bone following hydroxyapatite ceramic implantation J.F. Osborn 227
High resolution lattice imaging of hydroxyapatite R. Hodgskinson, W. Bonfield 233
pH, HA, TCP and Bioactivity B.J. Fellows, H.J. Oel 239
Section 6, Biological performance of poly-L-lactide
In vivo and in vitro degradation of poly(L-lactide) used for fracture fixation R.R.M. Bos, F.R. Rozema, G. Boering, J.W. Leenslag, A.J. Pennings, A.B. Verwey 245
Absorbable bone-plates and screws for the fixation of malar fractures F.R. Rozema, R.R.M. Bos, G. Boering, J.W. Leenslag, A.J. Pennings, A.B. Verwey 251
Release and degradation characteristics and antitumor effect of adriamycin-containing poly-L-lactic acid microspheres 0. Ike, S. Watanabe, T. Nakamura, R. Wada, S.-H. Hyon, S. Hitomi, Y. Ikada, Y. Shimizu... 257
Macrophage activation for antitumor function by a muramyl dipeptide derivative encapsulated in polyactide microspheres Y. Tabata, Y. Ikada 263
Section 7. Soft tissue-biomaterial interactions
Cellular synthesis performance in different collagen extraction mediums J. Dohrenbusch, Μ. Kern, Τ. Otterbach, Β. Klosterhalfen, Α. Valencia 269
Surface energy considerations in the adsorption of proteins to metals D.F. Williams, R.L Williams 275
Tissue compatibility from different high cross-linked colagen sponges after subcutaneous implantation in mice H.A. Richter, J. Buchenroth, S. Handt, N. Maurin, Ch. Mittermayer 279
Wound healing phenomena around permanent percutaneous implants in guinea pigs and rabbits J. A. Jansen, Κ. de Groot 285
Destruction of erytrocytes under sinusoidally fluctuating shear rate S. Hashimoto, A. Ishihara, T. Sasada 291
Modification of polyetherurethane for endothelial cell seeding W. Breuers, D. Klee, Η. Höcker, C. Mittermayer 297
Section 8. Biomaterial evaluation
Constitution of oxides on titanium alloys for surgical implants P.-A. Mäusli, J.P. Simpson, G. Burri, S.G. Steinemann 305
Microchardness, Young's modulus and mineral content in bone and a bone analogue G.P. Evans, J.C. Behiri, W. Bonfield 311
Monomeric reactive centres in polymeric prosthetic materials A. Bertoluzza, P. Filippetti, P. Monti, M.R. Tosi, R. Caramazza, M. Cellini 317
A computerisation programme for handling data on the biocompatibility of implant materials C. Zolezzi, A. Casanova, S. Stea, L. Pratelli, G. Ciapetti, A. Pizzoferrato 323
Mucin pellicles protect hydroxyapatite against decalcification A.V. Nieuw Amerongen, C.H. Oderkerk, E.C.I. Veerman, K. de Groot 327
XII
Immunochemical identification of proteins adsorbed onto hydroxyapatite after in vivo and in vitro incubation with serum and plasma E.C.I. Veerman, R.J.F. Suppers, C.P.A.T. Klein, K. de Groot, A.V. Nieuw Amerongen 331
Comparison of in vivo and in vitro protein adsorption patterns to bone substitutes E. C.I. Veerman, R.J.F. Suppers, C.P.A.T. Klein, K. de Groot, A.V. Nieuw Amerongen 337
Ultrastructural evaluation of different biomaterial phagocytoses by macrophages S. Guizzardi, G. Ciapetti, C. Tarabusi, S. Stea, A. Ruggeri, R. Riva, A. Pizzoferrato 343
Evaluation of adhesion capability of conjunctival Staphylococcus aureus on polymeric materials C. Arciola, P. Versura, G. Ciapetti, P. Monti, A. Pizzoferrato, R. Caramazza 349
Oxygen permeability through hydrogel membranes L. Nicodemo, F. Bellucci, C. Migliaresi, R. Le Rose, C. Carfagna, S. Nappi 355
The biocompatibility of intraocular-lens-haptics made of polypropylene and polymethylmethacrylate 361
Model for dynamic construction of isoelastic tubular prosthesis at the example of the trachea H.H. Schauwecker, J. Gerlach, H. Planck, E.S. Bücherl 371
The in vitro aging of polymers R. Mathys Jr., H. Weigum, P. Herzig, F. Bigolin 377
The corrosion fatigue properties of surgical implants in a living body M. Morita, H. Hayashi, T. Sasada, Y. Tsukamoto, M. Yamamoto 381
A study of the foaming ceramization process in the synthesis of porous phosphate glass-ceramics for bone implants F. Pernot, A. Kadom Rashid 387
Influence of silicone co-block on performance of polyetherurethane biomaterials R.J. Zdrahala, D.E. Spielvogel, D.D. Solomon 393
Section 9. Biocompatibility and biofunctionality of cardiovascular prothesis
The effects of lipid diet on long term patency rate of degradable polyurethane vascular prosthesis in pigs G. Galletti, S. Leonardi, G. Ussia, F. Farruggia, A. Salerno, S. Gogolewksi 399
Processed dermal sheep collagen (PDSC) as a small diameter vascular graft J.J.G. Bannenberg, A.C. van der Wal, P.J. Klopper 405
Bio-mechanical design of novel elastomeric vascular adhesive: significance of compliance matching T. Matsuda, T. Yamaguchi, K. Hayashi, T. Itoh, H. Iwata, N. Nakajima 411
Early stages of dystrophic calcification in bioprosthesis cardiac valves: experimental animal model G. Noera, C. Massini, G. Fattori, A. Incerti Medici, A.M. Gatti 417
Section 10. Biomechanics of bone
Osteoarthrosis and the mechanical behaviour of trabecular bone in the human femoral head K.E. Tanner, D.J. Sharp, C. Doyle, R.R.H. Coombs, W. Bonfield 423
An investigation into the transmission of shock through the vertebral column M. Müller-Gerbl, 0. Ennemoser, R. Putz 429
Elastic and anelastic microstrain measurement in human cortical bone M. Dabestani, W. Bonfield 435
Compressive behavior and water distribution of human lumbar vertebral disc by MRI T. Ushida, T. Tateishi, K. Honma. Y. Shirasaki, K. Hyodo 441
Contribution of mechanical factors to the pathogenesis of osteochondritis dissecans in the knee joint T. Nambu, E. Schneider, W. Bandi, S.M. Perren 447
Stabilization of distal radius fractures — biomechanical testing of K-wire- and polydioxanon-(PDS)-pins C. Krettek, R. Hoffmann, N. Haas 453
XIII
Section 11. Biomaterials in oro-facial surgery
Hydroxylapatite implants in periodontal bone defects in dogs G. L. de Lange, E.H. Burger, C. de Putter, Κ. de Groot 457
Loading permucosal dental implants of hydroxylapatite with orthodontic forces C. de Putter, G.L. de Lange, W. Hickory, K. de Groot, B. Prahl-Andersen 465
Submucosal dental implants of hydroxylapatite under fixed arid removable bridges F.L.J.A. de Wijs, J.A. van den Wijngaard, G.L. de Lange, Κ. de Groot, C. de Putter 471
The application of hydroxylapatite in endodontics W. van Welsenes, G.L. de Lange 477
Healing of the gingiva following installment of Biotes® implants in beagle dogs H. J.Y, van Drie, W. Beertsen, A. Grevers 485
Section 12, Controlled release
Preparation and properties of novel self-regulating membrane H. Iwata, T. Matsuda 491
Microencapsulation of islets in novel polyion-complex membranes and its evaluation as bioartificial pancreas H. Iwata, T. Matsuda, H. Amemiya, H. Takano, T. Akutsu 497
Author Index 503 Subject Index 506
Implant Materials in Biofunction, 429 edited by C. de Putter, G.L. de Lange, Κ. de Groot and A.J.C. Lee, Advances in Biomaterials, Volume 8, Elsevier Science Publishers B.V., Amsterdam, 1988 — Printed in The Netherlands
AN INVESTIGATION INTO THE TRANSMISSION OF SHOCK THROUGH THE VERTEBRAL COLUMN
M.MUELLER-GERBL 1,0.ENNEMOSER 2 and R.PUTZ 1
1 A n a t o m i s c h e s I n s t i t u t , L e h r s t u h l 1 1 1 , A l b e r t s t r . 1 7 f D-7800 F r e i b u r g 2 I n s t i t u t für M e d i z i n i s c h e P h y s i k , M ü l l e r s t r . 4 4 , A-6020 I n n s b r u c k
ABSTRACT
S i x f r e s h s p e c i m e n s from t h e lumbar v e r t e b r a e u/ere e x a m i n e d under m e c h a n i c a l s t r e s s ( a blow a p p l i e d t o t h e un d e r s u r f a c e o f t h e lowe s t v e r t e b r a w i t h or w i t h o u t l o a d i n g o f t h e s p e c i m e n from a b o v e ) . To d e t e r m i n e t h e r e l a t i v e i m p o r t a n c e of t h e t r a b e c u l a r bone and i t s c o n t a i n e d marrow a s ^ h o c k - a b s o r b e r s 1 i n t h e s p i n a l column, the s p e c i m e n s were e x a m i n e d a f t e r r e m o v a l of spongy bone and marrow and s u b s e q u e n t f i l l i n g w i t h P a l a c o s . I t h a s been d e m o n s t r a t e d t h a t b o t h bone and marrow a r e n e c e s s a r y f o r e f f i c i e n t damping, e s p e c i a l l y i n t h e h i g h e r f r e q u e n y r a n g e , a l t h o u g h t h e i r i m p o r t a n c e d e p e n d s on t h e f r e q u e n c y i n d e c i b e l s o f t h e t r a n s m i t t e d s h o c k . The i n t e r v e r t e b r a l d i s c s a r e i m p o r t a n t when b l o w s a p p l i e d t o t h e column a r e l i g h t , and t h e n o r m a l k y p h o s e s and l o r d o s e s a l s o p l a y a p a r t i n t h e a b s o r p t i o n of s h o c k .
INTRODUCTION
I n t h e c o u r s e of e v e r y d a y l i f e t h e v e r t e b r a l column i s
s u b j e c t e d t o a l a r g e number of bl o w s w h i c h i t can o n l y s u s t a i n
w i t h o u t damage f o r any l e n g t h o f t i m e i f i t s s h o c k - a b s o r b i n g
mechanism i s f u n c t i o n i n g s a t i s f a c t o r i l y . T h i s c a p a c i t y f o r s h o c k
a b s o r p t i o n and s h o c k t r a n s m i s s i o n i s s t i l l o n l y i m p e r f e c t l y
u n d e r s t o o d . I t i s q u i t e u n c e r t a i n , f o r i n s t a n c e , what t h e
r e s p e c t i v e r o l e s o f t h e i n t e r v e r t e b r a l d i s c and t h e v e r t e b r a l body
i t s e l f may be.
Our p r e v i o u s i n v e s t i g a t i o n s ( r e f . 1 ) on s e v e r a l v o l u n t e e r s have
e s t a b l i s h e d t h a t an e s s e n t i a l component o f t h i s mechanism i s
p r o v i d e d by t h e n a t u r a l c u r v e s o f t h e column. W h i t e and P a n j a b i
( r e f . 2 ) have a l s o e x p r e s s e d t h e o p i n i o n t h a t i t s n o r m a l
a n a t o m i c a l l o r d o s e s and k y p h o s e s a c t t o some e x t e n t a s s h o c k -
a b s o r b e r s .
N e v e r t h e l e s s , t h e s u p p o r t g i v e n by t h e s e c u r v e s i s , by i t s e l f ,
i n s u f f i c i e n t t o a c c o u n t f o r i t s c a p a c i t y t o a b s o r b s h o c k s w i t h o u t
430
b e i n g damaged. A c c o r d i n g to I n o u e ( r e f . 3 ) , t h e i n t e r v e r t e b r a l
d i s c s a c t a s s h o c k - a b s o r b e r s by a s s i m i l a t i n g c o m p r e s s i o n f o r c e s
a p p l i e d to t h e v e r t e b r a l column. T h i s s h o c k - a b s o r b i n g c a p a c i t y of
t h e d i s c i s , i n p a r t , d e p e n d e n t on t h e f a c t t h a t t h e a n u l u s f i b r o -
s u s c a n expand or b u l g e o u t w a r d s i n r e s p o n s e t o t h e ou t w a r d
t h r u s t of t h e n u c l e u s p u l p o s u s when i t i s under p r e s s u r e from i t s
n e i g h b o u r i n g v e r t e b r a e ( r e f , 2 ) . I n o u e m a i n t a i n s , h owever, t h a t
t h e c a r t i l a g i n o u s e n d - p l a t e s p l a y an i m p o r t a n t p a r t t o o .
T r a b e c u l a r bone i s a l s o s u p p o s e d t o c o n t r i b u t e t o w a r d s t h e
a b s o r p t i o n o f i m p a c t s ( r e f . 4 ) , and i t s f u n c t i o n i s c o n s i d e r e d t o
be g r e a t l y e n h a n c e d by t h e p r e s e n c e o f bone-marrow ( r e f . 5 ) .
uJe a r e h e r e c o n s i d e r i n g t h e q u e s t i o n : what p a r t does t h e v e r
t e b r a l body, i n c l u d i n g i t s c o n t a i n e d marrow, p l a y i n t h e
a b s o r p t i o n of s h o c k ?
MATERIAL
liie u s e d s i x f r e s h s p e c i m e n s from t h e i n t a c t lumbar column,
b e i n g c a r e f u l t o c h e c k t h a t t h e r e was n o t h i n g i n t h e h i s t o r y of
any of them t o s u g g e s t p a t h o l o g i c a l c h a n g e . B e f o r e we began, we
o b t a i n e d AP and l a t e r a l x - r a y s of e a c h s p e c i m e n . The age of t h e
s u b j e c t s ( f o u r male and two f e m a l e ) l a y between 15 and 66 y e a r s .
E a c h s e c t i o n of t h e column c o n s i s t e d o f 2 t o 5 "Bewegungssegmente"
(JUNGHANNS 1 " l o c o m o t i o n s e g m e n t " ) ( T a b l e 1 ) .
TABLE 1
S p e c i m e n Age Sex Number of s e g m e n t s
No.1 60 y e a r s male 4 No.2 65 y e a r s f e m a l e 5 No.3 66 y e a r s f e m a l e 2 No.4 57 y e a r s male 3 No.5 15 y e a r s male 2 No.6 45 y e a r s male 2
METHODS
A ma c h i n e h a s been c o n s t r u c t e d w h i c h makes i t p o s s i b l e t o
s u b m i t s e g m e n t s of t h e v e r t e b r a l column t o v a r i o u s d e g r e e s of
l o a d i n g from above ( F i g . 1 ) . I t i s a l s o p o s s i b l e w i t h t h i s machine
to a p p l y s h o c k s of d i f f e r e n t s t r e n g t h s ( 2 - 6 f g f ) t o t h e l o w e s t
v e r t e b r a from u n d e r n e a t h . I n o r d e r t o me a s u r e t h e f o r c e of t h e
s h o c k , we s c r e w e d a c c e l e r o m e t e r s ( I C P A c c e l e r o m e t e r ; PCB Model No.
303 A l l - P i e z o - t r o n i c s - r a n g e : + 10 t o - 10 g) t o t h e s p i n e s
o f t h e l o w e s t and h i g h e s t v e r t e b r a e . The d a t a c o l l e c t e d were t h e n
t r a n s m i t t e d t h r o u g h an A D - c o n v e r t e r d i r e c t l y i n t o a PC f o r f u r t h e r
431
c o m p u t a t i o n . The d i s t o r t i o n of t h e i n t e r v e r t e b r a l d i s c s was
m e a s u r e d w i t h s t r a i n g auges (HBM DMD 2 0 ) s t i t c h e d t o them i n a
h o r i z o n t a l p o s i t i o n , and t h e v a l u e s of t h e s i g n a l s r e g i s t e r e d w i t h
a y t - w r i t e r .
F i g u r e 1 : D i a g r a m m a t i c r e p r e s e n t a t i o n of t h e a p p a r a t u s u s e d f o r
t h e e x p e r i m e n t
I n o r d e r t o c a l c u l a t e t h e f r e q u e n c y - d e p e n d e n c e of t h e s h o c k
a t t e n u a t i o n , a d i s c r e t e F o u r i e r t r a n s f o r m was u s e d t o o b t a i n t h e
f r e q u e n c y s p e c t r u m of t h e a c c e l e r a t i o n v a l u e s . S i n c e t h e maximum
F o u r i e r c o e f f i c i e n t s l a y i n t h e f r e q u e n c y r a n g e of 100 - 200 Hz,
s t e p s a t i n t e r v a l s of 5 Hz from 5 t o 250 Hz were more c l o s e l y
i n v e s t i g a t e d . I f one d i v i d e s t h e v a l u e o f t h e F o u r i e r a m p l i t u d e
m e a s u r e d by t h e h i g h e r r e c o r d i n g p o s i t i o n w i t h t h a t m e a s u r e d by
t h e l o w e r , a v a l u e f o r t h e s o - c a l l e d " f r e q u e n c y r e s p o n s e f u n c t i o n "
i s o b t a i n e d . The v a l u e of t h i s f u n c t i o n - w h i c h i s measured i n
d e c i b e l s - p r o v i d e s i n f o r m a t i o n a b o u t t h e r e l a t i v e d e p e n d e n c y o f
t h e s h o c k - a b s o r b i n g c a p a c i t y on t h e f r e q u e n c y . N e g a t i v e d e c i b e l
v a l u e s s i g n i f y e f f i c i e n t s h o c k - a b s o r p t i o n . P e a k s w i t h p o s i t i v e
d e c i b e l v a l u e s i n d i c a t e r e s o n a n c e p o i n t s , w h i c h means t h a t a t t h i s
f r e q u e n c y t h e s h o c k i s i n c r e a s e d .
432
RESULTS
The a b i l i t y o f t h e s p e c i m e n s t o a b s o r b s h o c k d e t e r i o r a t e s i f
t h e e x p e r i m e n t i s c o n t i n u e d f o r t o o l o n g ( F i g . 2 . ) · W i t h i n 35
m i n u t e s of l o a d i n g t h e s p e c i m e n w i t h 20 kg t h e g r e a t e r p a r t of t h e
f r e q u e n c y r e s p o n s e f u n c t i o n r e m a i n s i n t h e n e g a t i v e r a n g e ; i n
o t h e r w o r d s , s h o c k - a b s o r p t i o n i s e f f i c i e n t . I f , h o w e v e r , a s t h e
e x p e r i m e n t i s c o n t i n u e d , t h e f r e q u e n c y r e s p o n s e f u n c t i o n b e g i n s t o
s h i f t i n t o t h e p o s i t i v e r a n g e , t h e c a p a c i t y f o r s h o c k - a b s o r p t i o n
becomes l e s s and l e s s .
12
OD -6 3 -12
υ 12
Ml
=-12
-6
-12
AFTER 135 MIN
SPINE NR.: 2
AFTER 120 MIN
SPINE NR.: 2
AFTER 35 MIN
50 100 150
FREQUENCY
200
(Hz)
250
12
6
0
ω -6
ο Μ
6 ÜJ w ο ο
6 ÜJ
-12
ÜJ 12 α
0
-6
-12
FILLED WITH PALAKOS
SPINE NR.: 5
WITHOUT CANCELLOUS BONE
SPINE NR.
BEFORE PREPARATION
50 100 150
FREQUENCY
200
(Hz)
250
F i g . 2 F i g . 3
F i g u r e 2 : F r e q u e n c y r e s p o n s e f u n c t i o n and i t s d e p e n d e n c e on
t h e d u r a t i o n o f t h e e x p e r i m e n t .
F i g u r e 3 : F r e q u e n c y r e s p o n s e f u n c t i o n i n t h e i n t a c t s p e c i m e n ( l o
wer c u r v e ) a f t e r r e m o v a l o f t h e spo n g y bone and marrow ( m i d d l e
c u r v e ) and t h e i r r e p l a c e m e n t w i t h P a l a c o s ( u p p e r c u r v e ) i n s p e c i m e n
No.5
433
I n o r d e r t o a s s e s s t h e p a r t p l a y e d by t h e v / e r t e b r a l b o d i e s i n
a b s o r b i n g s h o c k , we removed t h e t r a b e c u l a r bone from t h e m i d d l e
v e r t e b r a and f i l l e d i t up w i t h m e t h y l m e t h a c r y l a t e ( P a l a c o s ) i n
s p e c i m e n s No.5 and 6. F i g . 3 shows t h e b e h a v i o u r of s p e c i m e n No.5
a t a l l s t a g e s o f t h e p r o c e d u r e : w h i l e s t i l l u n t o u c h e d , a f t e r t h e
r e m o v a l o f t h e s p o n g i o s a and f o l l o w i n g i t s r e p l a c e m e n t w i t h
P a l a c o s . A f t e r t h e s p o n g i o s a had been t a k e n away from t h e m i d d l e
v e r t e b r a t h e f r e q u e n c y r e s p o n s e f u n c t i o n showed f e w e r p e a k s . I f
t h e f r e q u e n c y ( a b s c i s s a ) i s above 100 Hz, t h e c o r r e s p o n d i n g
d e c i b e l v a l u e ( o r d i n a t e ) i s l o w e r t h a n w i t h t h e i n t a c t s p e c i m e n .
I n c o n t r a s t t o t h i s , w i t h f r e q u e n c i e s below 100 Hz, t h e d e c i b e l
v a l u e r i s e s 1 . 7 - f o l d , w h i c h c o r r e s p o n d s t o a d e t e r i o r a t i o n i n t h e
damping e f f e c t . A f t e r we had f i l l e d t h e v e r t e b r a l body w i t h
P a l a c o s , t h e f r e q u e n c y r e s p o n s e f u n c t i o n ( p a r t i c u l a r l y i n t h e
h i g h e r f r e q u e n c y r a n g e ) showed a 3 . 3 - f o l d i n c r e a s e , w h e r e a s o n l y a
1 . 4 - f o l d i n c r e a s e was f o u n d i n t h e l o w e r r a n g e . S p e c i m e n No.6
r e s p o n d e d i n t h e same way.
The more u n i f o r m t h e c u r v e o f t h e a c c e l e r a t i o n v a l u e s , t h e more
c o n t r a d i c t o r y d i d t h e m e a s u r e m e n t s p r o d u c e d by t h e s t r a i n g a uges
become. A r h y t h m i c a l o s c i l l a t i o n was f ound i n a l l c a s e s . E n t i r e l y
a g a i n s t o u r e x p e c t a t i o n s , t h e i n i t i a l r e s p o n s e was one of c o n t r a c
t i o n . U/ith o n l y one s p e c i m e n d i d t h e o s c i l l a t i o n of t h e i n t e r v e r
t e b r a l d i s c b e g i n w i t h e x p a n s i o n .
D I S C U S S I O N
The d e t e r i o r a t i o n o f damping e f f i c i e n c y o b s e r v e d i n t h e
v e r t e b r a l c o l u m n a s t h e s t r e s s a p p l i e d t o i t c o n t i n u e s , i s
p r o b a b l y due t o t h e e x p u l s i o n of f l u i d from t h e i n t e r v e r t e b r a l
d i s c i n t o t h e s u r r o u n d i n g t i s s u e s . L o n g e r i n t e r v a l s between t h e
b l o w s a l l o w s u f f i c i e n t t i m e f o r t h i s f l u i d t o be r e p l a c e d .
The e f f e c t o f r e m o v i n g t h e s p o n g i o s a from t h e v e r t e b r a l body
and r e p l a c i n g i t w i t h P a l a c o s c l e a r l y d e m o n s t r a t e s t h e
c o n t r i b u t i o n o f t h e t r a b e c u l a r bone and i t s c o n t a i n e d marrow t o
t h e damping c a p a c i t y o f t h e w h o l e column, t h e d e g r e e of w h i c h i s ,
h o w e v e r , f r e q u e n c y - d e p e n d e n t . I t i s more i m p o r t a n t i n t h e h i g h e r
f r e q u e n c y r a n g e t h a n i n t h e l o w e r .
The s u p p o r t c o n t r i b u t e d t o s h o c k - a b s o r p t i o n by t h e d i s c s comes
t o t h e f o r e when t h e b l o w s a r e weak. With a f r e q u e n c y of more t h a n
100 Hz - t h a t i s t o s a y , f o l l o w i n g s t r o n g e r b l o w s - t h e s i g n i f i
c a n c e o f t h e s p o n g i o s a / m a r r o w s y s t e m i n c r e a s e s . J u d g i n g from t h e
434
damping c u r v e s o b t a i n e d , t h e i n s i d e of t h e v e r t e b r a l body i s an
i m p o r t a n t component of t h e damping s y s t e m .
liie have h e r e an e x p e r i m e n t a l c o n f i r m a t i o n of t h e v i e w s
e x p r e s s e d by P a t w a r d h a n and h i s c o - w o r k e r s (1 9 8 5 ) on t h e r o l e of
spongy bone; and our r e s u l t s a l s o a g r e e w i t h t h e f i n d i n g s of Hayes
e t a l . ( 1 9 7 6 ) , who a t t r i b u t e d a s i m i l a r f u n c t i o n t o t h e bone-
marrow ·
T h i s means t h a t a l l t h e e l e m e n t s of J u n g h a n n s 1 " l o c o m o t i o n
s e gment", i n c l u d i n g b oth v e r t e b r a l b o d i e s , a r e n e c e s s a r y f o r t h e
damping s y s t e m of t h e s p i n a l column t o be f u l l y e f f e c t i v e ; and
o n l y when a l l p a r t s a r e i n t a c t and f u n c t i o n i n g p r o p e r l y c a n b l o w s
be e f f e c t i v e l y t a k e n up and r e n d e r e d i n n o c u o u s .
E f f i c i e n t l y t r a i n e d back m u s c l e s a r e a l s o , of c o u r s e , p r e s u p
p o s e d . They s h o u l d be i n a p o s i t i o n t o c o n t r o l t h e f l e x i o n of t h e
whole column i n an o p t i m a l manner ( r e f . 1 ) .
The p a r a d o x o f t h e r h y t h m i c a l o s c i l l a t i o n of t h e i n t e r v e r t e b r a l
d i s c , w h i c h i n i t i a l l y shows e i t h e r c o m p r e s s i o n or e x p a n s i o n , i s
p r o b a b l y bound up w i t h t h e d i f f e r e n t d i r e c t i o n and p u l l of t h e
f i b r e s of t h e a n u l u s f i b r o s u s . V e r y l i k e l y i t s t e x t u r e - t h e
l a y o u t o f t h e f i b r o u s l a m e l l a e - i s r e s p o n s i b l e .
REFERENCES :
1 P u t z , R., E n n e m o s e r , 0. » K ü n s t l e , M . (1981 ) : Zum D ä m p f u n g s v e r h a l t e n d e r W i r b e l s ä u l e . V e r h . A n a t . G e s . 7 5 , 2 5 1
2 W h i t e , A . A . , P a n j a b i f M . M . ( 1 9 7 8 ) : C l i n i c a l b i o m e c h a n i c s of t h e s p i n e , 2-17. P h i l a d e l p h i a : J . B . L i p p i n c o t t Co.
3 I n o u e , H . ( 1 9 8 1 ) : T h r e e - d i m e n s i o n a l a r c h i t e c t u r e of lumbar i n t e r v e r t e b r a l d i s c s . S p i n e 6,139-146
4 P a t w a r d h a n , A . , V a n d e r b y , R . , K n i g h t , G . W . , G o g a n , W . J . , L e v i n e , P . D . ( 1 9 8 5 ) : B i o m e c h a n i c s of t h e s p i n e , 1 3 9 - 1 5 0 , i n : A t l a s of O r t h o t i c s , S t . L o u i s : The C.V.Mosby Company
5 H a y e s , W . C . , C a r t e r , D . R . ( 1 9 7 6 ) : The e f f e c t o f marrow e n e r g y abs o r p t i o n of t r a b e c u l a r bone. P r e s e n t e d a t t h e 22nd A n n u a l M e e t i n g o f t h e O r t h o p a e d i c R e s e a r c h S o c i e t y , New O r l e a n s
6 K r ä m e r , J . ( 1 9 7 3 ) : B i o m e c h a n i s c h e V e r ä n d e r u n g e n im l u m b a l e n Bewegungssegment, d i e W i r b e l s ä u l e i n F o r s c h u n g und P r a x i s 58, H i p p o k r a t e s S t u t t g a r t