Articular cartilage in relation to loading and articulation

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ARTICULAR CARTILAGE _】村 R 範 LATION

TO LOAD:NG AND ARTICULATION

A.S. ARAVIND

CENTRE FOR BIOMEDICAL ENGINEERING

submitted

in fulfiHment of the requirements of the degree of DOCTOR OF PHILOSOPHY

tothe 翻

-NDIAN INST 汀 UTE OF TECHNOLOGY, DELHI

DECEMBER, 1997

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CERTI ACATE

This is to certify 'that the thesis entitled "ARTICULAR CAR1LAGE I N RELA11ON TO LOADING AND ARTICULATION'、 being submifited by A.S.Aravind for the award of the degree of DOCTOR OF PHILOSOPHY,1 s a record of the original bonafide research work carried out by hirn. He has worked under our joint guidance and supervision and hasfulfilled the requirementsforthe submission of this thesis. The results presented in this thesis have not been submilted in part or full to any other University or Institute for awa旧of any degree/diploma.

Dr. R. K. Saxena Assistant Professor

Centre for Biomedical Engg.

Indian Institute of Technology New Delhi-i 10016.

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1「 1 フ 11 り

Dr.K. B. Sahay Professor

Center for Biomedical Engg.

Indian Institute of Technology New Delhi -110016.

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ACKNOWLEDGEMENTS

、，ぬ肱み如

Ya Vimuktayell That which liberates is Know'edge

T十115 endeavour has been a vefy valuabje 】earnjng process and for me thjs eXI〕e「lenCe WaS a rewa「d In ltself. The knowledge gained in this process was the leElllsatlon of the power of true questioning and the trUth that it 15 equally important to flslく tlle 1-igllt qUestiorls to obta-n the rlght answers. It 15 in this Sense that right 1て11()wledge Ieads to rightしJnderstanding and to the above vedic definition of knowledge.

This effort as of any other, had its share of periods of smooth running and o1)stacIes and blocks. Every step could be taken only because of the pushes and pulls

「 eceived from many different people, especially so when things were low. Several poeple right from the 'lbutcher to the binder" have equal hand in the completion of this work. I sincerely thank every single contribution received towards this thesis, particularly the help received from all my friends.

I thank Prof. K.8. Sahay, with gratitude, who has been the backbone of the work.

He was always there as a sure support at all times and his fatherly wisdom and guidance

＼・'L1S my source of strength.

Dr. RK. S_欲ena, my other supervisor, has :een more than a supervisor. He, in his ease of approach, has cared for me and shov'（・red me with deep affection 磁 all

！、mes. His deep involvement in this work has I．・,rl干I great inspiration. for me. I am 1njehied to him for all this.

The Department with all its facuity cnd hr,1

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I cn able to provide the

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quired 1;c,tvices for the work. I thank the Head tor hcr supper; cind personal interest she evinced I11 tliI; work.

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1井崩聞r 、 IMWn

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My friends, elders and well wishers have held me by my hand and pulled me several times from my predicaments. I shall fail if」 do not recognise and acknowledqe the various helps received. I am grateful to my circle of friends, without whose help ond support this work and the learning process could not have been complete. My friends are my only wealth.

My family, parents, sister and wife are wholly responsible for making me whot I am today. I am nothing without them. I owe them my all

Sarve fihavan加Su競inah Om Shan助Sha回ih 訪antih

May aU be happy

May there be peace everywhere

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ABSTRACT

Articular cartilage is a biphasic tissue consisting of a solid and a fluid phase.

The load bearing capacity depends upon its matrix constituents. Hence the biphasic theory of articular cartilage proposed by Mow et al.,to characterise the biomechanical response of the tissue is a more realistic description of the tissue behaviour.

Biornechanical responses of articular cartilage are affected by mechanical factors and play an important role on the load bearing properties of the articular cartilage and also on the overall tissue physiology. Biomechanical behaviour of the tissue the result of the morphological structure and the biochemical composition of the tissue constituents. The cartilage properties have been studied in various ways. However the biphasic analysis and model have not been fully employed to understand and interpret the tissue property changes under loading.

The present study analyses the changes in the knee joint articular cartilage properties viz., morphological, biochemical and biomechanical when the knee joint is subjected to physiological and supra-physiological levels of loading and an attempt has also been made to analyse the correlations between the morphological and biochemical changes vis-a-vis the changes in the biomechanical prope比ies of the tissue.

The Chapter-i of the thesis is a general introduction to the subject which puts forth the perspective of the work and gives its scope and orientation. The Chapter-2 describes the location, structure, function and constituents of the articular cartilage.

Biochemistry of the constituents of the normal tissue along with their structural details is

『つ resented in a biomechanical perspective. Pathological conditions of the cartHage and their etiology are also discussed briefly for completeness.

Chapter-3, on literature-review, explores the evolution of the different models for cartilage tissue characterisation carried out by previous investigators. The works done

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structure follows. Details of tissue microscopy are described.

p roteoglycan description of

uniaxial filtration are also explained.

mechanical experimental

Details of punches and

tests under the stipulations of the hiphasic model are discu1 details for carrying out confined compression test, iriCierltntiori

Content: water content and tissue hydration techniques for light

test jigs for sample collection and cnrryir)rj

microscopy processing for

Biochemical procedures for the estin ir:itior i(if

for morphoiogical stud旧s of ti;sしJ e Sc anfing and transmis引C n 馴O（共「C) fl are described. 1ieri Un

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ーー■ ーく O n 打 by employing the biphasic theoッof the ca比ilage by various research勲1ミ； 1―「tヲ r（きVI E・しVE〕ぐ」

The effects of loading on the cartilage tissue matehal prnperties 1119 1〔〕tJll‘」1Y! 、。111，・f investigators are aiso presented. The review indicates that there（告×ist; a rit・t・（.1 f（〕r1 j controlled study of the load related changes occし』rrincj in the bfo)1fle（二1-ilrll〔二 al P'('i)‘・ft-（・11 of the tissue and examine the correlations with the norr〔き5「）ぐ）r lEJ i ri'J <】 i i1111〔1，・・。 ir i biochemical and morphological properties. The ch叩ter conciし1<ir r; vitll tt11・pr‘〕―〕―，・ill statement. Chapter-4 presents the development of the KLM biphn!;ic tir1・（)ry 、；「 lii，・

cartilage to obtain the constitutive relations of the triodel. i"h（・「r1() ri。・I C1(》 ir！。tltl iti'.'。・

equations have then been solved for the confined cor1lpresslor', irci'・「rt;rtiori i rri(i urn、 i×iii!

filtration problems.

Chapter-5 on materials and methods discusses hie desiqo of tirf・、き×1〕，・r ! r i i,1 r i ti il protocol that was adopted in this study. Pairs ol freshly nriputat贈〔j yni」 ri(1 brivir ii・1、r i『・，・

joints have been employed for this study. One of ther丁〕servr〕J rs（二（>nt"- >1 fl ti< I tfi,'("11i'・（

as experimental joint which was load tested. A specにlily cIer5iqneci kri<1," je〕1rit 1 irti「 :n―こitiri'1 machine has been used for loading and articulation of the kn（き（}jOir1tli. J"v〔> kIv，・1シ：rit-（〕11(1 with articulation were applied on the experimental kneりj ()l rl t『ら f ri「を1 11×（！ぐ j liきri<itii r)f tir r-‘・

(i) Moderate level of load equal to body weight of the animai and

(ii) High load equal to twice the body weight.

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The load related changes in the biomechanicat, morphological and biochemical properties observed in the articular cartilage are presented in Chapter-6. The articular cartilage tissue biomechanical properties have shown significant alterations when the jcints were subjected to high load and moderate load conditions together with charges in the morphological characteristics and alterations in proteoglycan and water contents.

The tissue fluid imbibition capacity also varied under different loading conditions. The SEM and TEM photo- micrographs and histological slide photographs of articular cartilage show the matrix and collagen arrangements and the changes therein when the knee joints were load tested.

Variations observed in biomechanical, morphological and biochemical propertleミ of the articular cartilage at moderate and high loadings have been correlated anc discussed in Chapter-7. Relevant conclusions have been drawn from these results in thE light of hiphasic theory and presented in Chapter-8. This has helped in furthering thE understanding of the tissue behaviour and response under different load conditions. ThE findings of this investigation arrive at the conclusion that tissue health and performancE improves under physiological levels of load whereas it deteriorates under supra physiological levels of loading. The chapter concludes with suggestions for furthe research in the field.

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Articular ca代Ilage propertles MorphoI0giCal p「OPeけles Biochem-ca」properties BjomechanjCaj propertjeS ArtiCular cartilage F)ropertles MorPho10giCal propertjes B」ochemica「 p「operties BiomechaniCfll p「ope巾es ArtiCular Cartllage「）rol)e_「tll、1！号 Morphological prol)（り『tles siochemical pro「）e「tles Biomechanical properties

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CHAPTER-8 8.1

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LIOGRAPHY Brief Biociata List of Publications

CONCLUSION AND FUTURE SCOPF1 Conclusion

Scope for further work _lti

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