UNIVERSITI PUTRA MALAYSIA

CLINICOPATHOLOGICAL CHANGES IN ADJUVANT INDUCED ARTHRITIS IN CANINE STIFLE JOINT

SITI NORHAYATI BT. ISMAIL

FPV 2001 4

CLINICOPATHOLOGICAL CHANGES I N ADJUVANT INDUCED ARTHRITIS IN CANINE STIFLE JOI NT

SITI NORHAYATI ST. ISMAIL

MASTER OF VETERINARY SCIENCE UNIVERSITI PUTRA MALAYSIA

2001

CLINICOPATHOLOGICAL CHANGES I N ADJUVANT I NDUCED ARTHRITIS I N CANINE STIFLE JOINT

BY

SITI NORHA YATI BT. ISMAIL

Thesis Submitted in Fulfilment of the Requi rement for the Degree of Master of Veterinary Science in the Faculty of Veterinary Medicine

Universiti Putra Malaysia

August 2001

CJ)edlcated to,

1vlummy and }lGafi,

Par your [aves, support and trust,

}leong, Ci/t crong, Isma and Cici

'IlianRJ for everytfiing ...

11

Abstract of thesis presented to the Senate of Un iversiti Putra Malaysia in fulf i lment of the requ i rement for the degree of Master of Veterinary Science

CLINICOPATHOLOGICAL CHANGES IN ADJUVANT INDUCED ARTHRITIS IN CANINE STIFLE JOINT

By

SITI NORHAYATI ST. ISMAIL

August 2001

Chairman Rashid Ibrahim, Ph.D.

Facu lty Veterinary M edicine

Osteoarthrit is is the most common joint d isease ,and cause of

physical d isabi l ity in man and animals, I t is a complex d isease with unknown

etiology. I ntra-articular inject ion of 1 m l . F reund's adjuvant was i noculated i nto

twenty-five adult Mongrel dogs weighing between 1 0-1 5kg, Osteoarthrit is was

induced in the left stifle joint , whi le the right joint act as a contro l . The dogs

were evaluated for cl in ica l evidence of joint heat, effusion and pain , and gait

abnormal it ies. Radiographs were obtained for soft tissue swel l ing ,

osteophytosis and degenerative changes . At the end of each tria l period (week

1, 2, 3, 4, 5) the dogs were euthanised . The left stifle joint were opened ,

examined grossly and the articular cart i lage and synovial membrane were

harvested and fixed for h istopathologic and electron microscopic studies.

HI

Cl in ical signs of joint swel l ing and pain upon palpation , weight bearing

lameness and reduced range of motion were observed withi n week 1 post­

i nocu lation . These signs were positively correlated with the acute pathological

lesions i n the synovial membrane and articular carti lage; and in rad iograph

evaluation. Radiograph study revealed evidences of soft tissue swel l ing ,

i ncreased intra-articular space, osteophytes formation ; the cl in ical s igns that

were suggestive of degenerative changes in osteoarthritis . However, plain

radiograph was found to be not informative enough in the early stage of

osteoarthritis. Gross changes duri ng post mortem revealed , swel l ing of the

adjacent soft tissue, hypertrophy of the joint capsule and synovial membrane,

and joint effusion . These were signs of inflammation of the jo int tissues and it

was bel ieved that the inflammatory process was one of the major factors in the

development of degenerative joint d isease. Lameness evaluation was

positively correlated with gross examination but negatively correlated with

rad iograph examination.

In h istopathology study, there were signs of i nflammation i n the synovial

membrane and formation of synovial pannus, which was thought to be related

with the development of degenerative changes on the articular carti lage.

Hyperplasia of intima and subint ima layer, edema and congestion ; flaking and

erosion i n articular cart i lage, were observed as early as week 1 p . i . U nder

scann ing electron microscopy, cart i lage fibri l lation and erosion, were observed

as early as week 1 p . i . S ignificant positive correlation between the histolog ical

changes in articular carti lage with changes in the synovial membrane

suggested that changes in the synovium preceded changes in the articular

IV

carti lage. The synovial membrane was highly vascularised , causes respond to

i njury more promptly. In a rticular cart i lage, it took t ime to heal s ince heal ing

depending on the depth of les ion .

In this study, the pathogenesis of osteoarthritis was d ivided into three

stages : the onset phase, which was observed with in one week post- induction ;

the second phase or the intermediate stage and the end phase. Each

structure, cel ls and tissues was found to have their own role in the production of

osteoarthritis . Study on the pathogenesis must emphasize on these structures

and cascade of events that occur during the production of osteoarthritis, which

wi l l aid in the treatment of osteoarthrit is . The cl in ica l , morphological and

microstructure changes that occurred in osteoarthritis had been characterised ,

but the role of each i n the aetio-pathogenesis of osteoarthritis, i s sti l l not rigidly

defined.

v

Abstrak tesis yang d ikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk Ijazah Master Sains Veterinar

PERUBAHAN PATOLOGI KLlNIKAL 01 OALAM INOUKSI ARTRITIS AOJUVAN PADA LUTUT ANJING

Oleh

SITI NORHAYATI BT. ISMAIL

Ogos 2001

Pengerusi Rashid Ibrahim, PhD.

Fakulti Perubatan Veterinar

osteoartritis adalah penyakit yang selalu menyerang sendi dan

menyebabkan ketidakstabi lan fizikal dalam manusia dan haiwan. la adalah

penyakit yang kompleks dan puncanya tidak diketahui . Suntikan intra-rawan

sebanyak 1 ml . adjuvan F reund's telah d iberikan kepada dua puluh l ima ekor

anj ing Mongrel dewasa yang mempunyai berat 1 0- 1 5 kg . Osteoartritis telah

dihasi lkan di dalam lutut k i ri anj ing sementara lutut kanan bertindak sebagai

kawalan. Anj ing tersebut telah dimantau secara kl inikal untuk mengesan

kehangatan sendi , efusi dan kesakitan, dan ketidaknormalan pergerakan.

Radiograf telah d iambi l untuk mengesan bengkakan tisu , osteopitosi dan

perubahan degenerasi . Pad a akhir setiap eksperimen (minggu 1 , 2, 3, 4 dan

5), anj ing-anj ing tersebut dimatikan. Lutut kiri anj ing-anj ing tersebut telah

d iperiksa secara mata kasar, sam pel sendi tu lang rawan dan n:embran sinovial

VI

telah d iambi l dan d iawetkan untuk pemerikasaan histopatologi dan m ikroskop

elektron .

Tanda-tanda kl in ikal seperti pembengkakan lutut, kesakitan ,

ketempangan dan kesukaran pergerakan telah d iperhatikan dalam minggu

pertama selepas induks i . Tanda-tanda tersebut berhubung kait secara positif

dengan lesi patologi akut di dalam membran s inovial dan tulang rawan; dan

uj ian rad iograf. Pemeriksaan radiograf pula menunjukkan tanda-tanda

kebengkakan t isu , tekanan t inggi antara rawan send i , pembentukkan osteopit;

adalah tanda-tanda k l in ikal yang menyokong penghasi lan degenerasi dalam

osteoartritis . Namun begitu, gambar radiograf d idapati t idak begitu meyakinkan

dalam pembentukan awal osteoartrit is. Pemerhatian mata kasar semasa

bedah s iasat menunjukkan pembengkakan t isu kel i l i ng sendi, ketebalan kapsul

sendi dan membran s inovia l . Tanda-tanda tersebut adalah tanda-tanda

inflamasi pad a tisu sendi l utut dan d ipercayai bahawa proses inflamasi adalah

salah satu p roses penting dalam pembentukan penyakit degenerasi sendi .

Uj ian ketempangan berhubung ka i t secara positif dengan ujian mata kasar,

tetapi berhubungkait secara negatif dengan uj ian radiograf.

Pemeriksaan histopatologi menunjukkan tanda-tanda inflamasi di dalam

membran s inovial dan pembentukkan sinovial panus yang d ipercayai

menpunyai kaitan dalam penbentukan degenerasi di dalam sendi rawan .

H iperplasia d i dalam lapisan s inovial i ntima dan subint ima, edema dan kongesi ;

kelupasan dan hakisan rawan , kel ihatan seawal minggu pertama selepas

induks i . Oi dalam imbasan mikroskop electron, pad a permukaan rawan,

Vll

fibrilasi dan kehausan rawan dapat diperhatikan seawal minggu pertama

selepas induksi . H ubungkait positif di antara perubahan lesi histologi dan

rawan sendi yand didapati di dalam membran sinovia l , meyakinkan bahawa

pembentukan lesi membran synovial akan menyebabkan pembentukan lesi

pad a rawan sendi . Membran synovial dipenuhi pembuluh , dan tindakbalas

terhadap kecederaan adalah lebih cepat. 8agi rawan sendi pu la , ,ia mengambil

masa untuk sembuh dan bergantung kepada kedalaman lesi.

Dalam kajian ini, patogenesis osteoartritis dapat dibahagikan kepada

tiga peringkat; peringkat permulaan , di mana perubahan diperhatikan dalam

masa seminggu selepas induksi , peringkat kedua ataupun pertengahan dan

peringkat akhir. Setiap struktur, sel dan tisu didapati mempunyai fungsi

masing-masing dalam pembentukan osteoartritis. Kajian mengenai

patogenesis mestilah mengambil kira pad a setiap struktur dan aliran proses

yang berlaku semasa pembentukan osteoartritis , yang dapat menolong dalam

mengubati penyakit osteoartitis. Perubahan klinika l , morfologi dan

mikrostruktur yang berlaku semasa osteoartritis telah dikaji, namun fungsi

setiap satu dalam etio-patogenesis osteoartritis masih belum dapat diterangkan

dengan pasti.

Vlll

ACKNOWLEDGEMENTS

All praise to Almighty Al lah, the Merciful and the Benevolent. Had it not

been due to H is wil l and favour, the completion of this study would not have

been possible.

I would l ike to express my deepest and sincere gratitude and

appreciation to my supervisor, Dr. Rashid Ibrahim, for his invaluable guidance,

advise, supervision, and support throughout the course of this study.

I wish to express my sincere gratitude to Associate Prof. Dr. Mohd Zamri

Saad and Dr. Md . Zuki B . Abu Bakar, who are my co-supervisor for their

valuable advice, support and continuous encouragement towards the

completion of this work. Special thanks and sincere appreciation to Dr. Ungku

Chulan U ngku Mohsin for h is resourceful comments and suggestions duri ng

completing this thesis .

My sincere thanks to Dr. Noor Bakry Hj . Mat Darus, mana�ing d irector of

Vet-Fine (M) Sdn . Bhd. ; the head department and supporting staff from the

Department of health , Dewan Bandaraya Kuala Lumpur, for providing the

experimental animals. I would like to thank the Institute Bioscience staff, Ms.

Azilah Ab. Ja l i l , Mr . H o O i Kuan, Ms. Su leka and Ms. Faridah Akmal . Not

forgett ing, our University Veterinary Hospital supporting staff; Pn . Norain i

Othman (surgery) , Mr. Osman Asnawi (Radiology) , Mr. Palaniandy Malyandy

and Mr Arumugam Iyasamy; from histology laboratory, Mr. Jamil Samad; from

IX

post mortem laboratory, Mr. Ghazal i Md. Yusoff, Mr. Noraziman Su la iman and

Mr. Apparau Somanaidu; from cl in ical pathology laboratory, Mr. Mohd Halmi

Oth man and Mr. Abdul lah M isron ; and lastly Mr. Zaid Othman and Mr.

C hamadre Vengadasamy for their help throughout the course of this study.

I have also been very fortunate in receiving assistance from a number of

my col leagues and friends. Many of them went out of their way to assist me

and it would not be possible to name al l of them . However I wish to express my

sincere g ratitude to Dr . Loqman Mohamad Yusof (veterinary surgeon i n

univers ity veteri nary hospital and a lecturer) , my col leagues ; Dr. Zurina Raml i ,

Dr . Anun Man , Dr . Zamirah Zai na l Abid in , D r. Marina Hassan , Dr . Yuslan

Sanuddin , Dr. Ronald F rancis and D r. Wan Mastura Shaik Mossadeq for their

help and support in materia l iz ing my research .

To one and al l whom I may have inadvertently left out, thank you .

Last but not least, to my mother, father and my fami ly, thank you for their

support and trust.

x

I certify that a n Examination Committee met on 1 3th August 2001 to conduct the fina l examination of Sit i Norhayati Bt. Ismai l on her Master of Veterinary Science thesis entitled "Cl in icipathological Changes in Adjuvant I nduced Arthritis in Canine Stifle Joint" in accordance with U n iversiti Pertan ian Ma laysia (H igher Degree) Act 1 980 and U niversiti Pertan ian Malaysia (H igher Degree) Regu lations 1 98 1 . The Committee recommends that the candidate be awarded the relevant degree. Members of the Examinat ion Committee are as fol lows:

SHANTH I GANABADI , Ph.D . Faculty o f Veterinary Medicine U niversit i P utra Malaysia (Chairman)

RASH I D I BRAH IM , Ph .D . Faculty o f Veterinary Medicine U n iversiti Putra Malaysia (Member)

MOHO ZAMRI SAAD, Ph .D . Associate Professor Faculty of Veterinary Medicine Un iversiti Putra Malaysia (Member)

MD. ZUKI ABU BAKAR, Ph .D . Faculty o f Veterinary Medicine Universiti Putra Malaysia (Member)

---�:::�------------------------

Mo��ciL l MOHAYID IN , Ph .D . Professor/Deputy Dean of Graduate School , U niversiti Putra Malaysia

Date :_2_

5_

SE_P_

20_0'

__

Xl

This thesis submitted to the Senate of Un iversiti Putra Malaysia has been accepted as fu lf i lment of the requirement for the degree of Master of Veterinary Science.

AINI IDERIS, Ph .D. P rofessor/Dean of Graduate School, U niversiti Putra Malaysia

Date:

XlI

08 Nnv 2001 -------------------

DECLARATION

I hereby declare that the thesis is based on my orig inal work except for quotat ions and citat ions, which have been duly acknowledged . I a lso declare that it has n ot been previously or concurrently submitted for any other degree at UPM or other institutions.

S ITI NORHAYATI BT. ISMAIL

Date: ,�-� - �oo \

Xlll

DEDICATION ABSTRACT

TABLE OF CONTENTS

ABSTRAK ACKNOWLEDGEMENTS APPROVAL SHEETS DECLARATION FORM LIST OF TABLES LIST OF FIGURES LIST OF PLATES LIST OF ABBREVIATIONS

CHAPTER

1 .0

2 . 0

INTRODUCTION 1 . 1 General I ntroduction 1 .2 Osteoarthritis Study 1 . 3 Study on Joint Diseases in Animals and Humans 1 .4 Objectives

LITERATURE REVIEW 2 . 1 Structures and Functions of Stifle Joint

2 . 1 . 1 Anatomy and Physiology of the Stifle Joint 2 . 1 .2 Articular Carti lage 2 . 1 . 3 Joint Capsule and Synovial Membrane

2 .2 Animal Models in Arthritis Research 2 .2 . 1 Rat Air Pouch 2 .2 . 2 Arthritis I nduction

2 . 2 . 2 . 1 Physical I nduction 2 .2 .2 .2 Surg ical Induction 2 .2 . 2 . 3 Art icular I rritants

2 . 3 Morphological Study 2 . 3 . 1 Gross Examination 2.3.2 Scanning Electron Microscopy Study

2 .4 C l inical Study 2 .4 . 1 Lameness Evaluation 2 .4 .2 Radiographic Evaluation

2 .5 Microstructure Study 2 . 5 . 1 H istopathological Study

XIV

Page i i i i i vi IX

xii x i i i XVI

xvii xvi i i

xxi

1 1 2 3 4

5 5 5 7 1 1 1 4 1 6 1 8 1 8 1 9 20 26 26 27 32 32 36 38 38

3 .0 GENERAL MATERIALS AND METHODS 44 3 . 1 Experimental Animals 44 3.2 Experimental Design 44 3.3 I nduction of Arthritis 45

4 .0 CLIN ICAL ASSESSMENT AND GROSS CHANGES ON THE STIFLE JOINT FOLLOWING EXPERIMENTAL OSTEOARTHRITIS 48 4.1 I ntroduction 48 4.2 Material s and Methods 5 1

4.2. 1 Cl inical Assessment 5 1 4.2.2 Lameness Evaluation 5 1 4.2 .3 Radiographic Assessment 52 4.2.4 G ross Necropsy 53 4 .2.5 Statistical Analysis 54

4 .3 Results 55 4 .3 . 1 Lameness Evaluation 55 4.3.2 Radiographic Evaluation 56 4 .3 .3 Gross Examination 56 4 .3 .4 Correlation Between Clin ical Evaluation and Gross

C hanges 57 4.4 Discussion 72

4.4. 1 Summary 78

5 .0 M ICROSCOP I C STUDY ON THE ARTICULAR CARTILAGE AND 80 SYNOVIAL MEMBRANE OF THE STIFLE JOINT FOLLOWING

6 .0

AN EXPERIMENTAL OSTEOARTHRITIS 5.1 I ntroduction 80 5 .2 Materia ls and Methods 83

5.2 . 1 Histopathology 83 5 .2 .2 Scanning E lectron Microscopy 85 5.2 . 3 Statistical Anaylsis 87

5.3 Results 87 5 . 3.1 H istopathology 87 5.3 .2 Scanning Electron Microscopy Study 88 5 .3 .3 Correlation Between Scanning Electron Microscopy 89

Study and Histopathological Study 5.4 Discussion 100

5.4. 1 S ummary 105

GENERAL D ISCUSSION 6. 1 Conclusion

106 1 15

B IBLI OGRAPHY APPENDICES VITA

1 17 140 145

xv

LIST OF TABLES

Table Page

4 . 1 Lameness scoring system 52

4 .2 Radiographic evaluation scoring 53

4 .3 Gross lesion scoring for articular carti lage, synovium and 54 fibrous capsule

4 .4 Results for clinical evaluation and gross changes 58

5 . 1 Lesion score for m icroscopic changes i n synovial membrane 84

5 .2 Lesion score of microscopic changes on articular carti lage 85

5 .3 Lesion score on the articular surface under SEM 86

5 .4 Results of lesion score in the articular cart i lage and synovial 90 membrane

XVI

Figure

2 . 1

2 .2

2 .3

3. 1

4.1

4.2

5 . 1

LIST OF F IGURES

Page

Schematic d rawing of articular cartilage h istology showing its 8 layers and fibri l arrangement. (A) Surface membrane. (8) Tangential zones. (C) I ntermed iate zones. (0) Radial zone. (E) Calcified zone. (F) Subchondral zone. (G) Tidemark. (H) Fibri ls or 'wickets' . Source: Piermattei and Flo, 1 997

A schematic d rawing of a longitudi na l section of a knee jo int of an adult man . The plane of the section that i s i l lustrated in the main drawing is indicated in the inset (upper right). Source: Ham, 1 974

A schematic d rawing of a cross section of normal articular carti lage. Source: Johnston , 1 997

Summary of materials and methods

Graph of mean c l in ical score for lameness evaluation

G raph for mean c l in ical score for lameness and rad iographic evaluation and mean lesion score for gross changes

The mean lesion scoring fol lowing microscopic study

XVll

1 4

4 1

47

59

59

9 1

LIST OF PLATES

Plate Page

4. 1 Photograph of the stif le joint; (a) Right stif le jo int; normal and 60 non-induced (b) Left stifle joint . Day 1 p . i . the stifle jo int is swollen , and presence of haematoma (arrow) at the s ite of injection.

4 .2 Photograph of the stifle jo int ; (a) R ight stifle jo int ; normal and 6 1 non-induced. (b) Left stifle joint . Day 3 p . i . , the stifle joint is swollen (arrow) , heat and pain were detected upon palpation.

4 .3 Photograph of the left stifle jo int . Weight bearing lameness 62 was evidence on day 1 p . i .

4 .4 Radiograph of the stifle joint . (a) Right stifle jo int ; normal and 63 non-induced. (b) Left stifle jo int . At week 1 p . i . , there are evidence of osteophyte formation (big a rrow head) appear as bony outgrowth and soft tissue swel l ing (sma" arrow head) . Lateral view.

4 .5 Radiograph of the stifle jOint. (a) Right stifle joint ; normal and 64 non i nduced . (b) Left stifle jo int . I ncreased intra-articular space (black a rrow) and swel l ing of the f ibrous capsule (white a rrow) were evidenced in week 2 p . i . Anterio-Posterior view

4 .6 Radiograph of the stifle joint . (a) Right stifle joi nt ; normal and 65 non-induced . (b) Left stifle joint . I ncreased i ntra-articu lar space (black a rrow) and sl ight soft tissue swel l i ng (wh ite a rrow) were evidence in week 3 p . i . Anterio-Posterior view

4 . 7 Rad iograph of the stifle jo int . (a) Right stifle jo int ; normal and 66 non-induced . (b) Left stifle jo int . At week 5 p . i . , there is a sma" amount of periosteal new bone formation (osteophyte formation) , which appears as sl ight rad io-dense area at the medial and lateral tibia (sma" arrow) , an increased intra­a rt icular space and osteolysis (arrow head) . Anterio-Posterior view.

4 .8 Radiograph of the stifle joint . (a) Right stifle joint ; normal and 67 non-induced (b) Left stifle joint . A t week 5 p.L, there is evidence of osteophyte formation (arrow) appear as l ips of new bone around the edge of the joint . Lateral view

XVlll

4.9 Photograph of the stifle joint. (a) Right stifle joint; normal and 68 non-induced . (b) Left stifle joint. Thickening of the articular cartilage especial ly at the troclear groove (TG) and troclear ridge (TR) and hypertrophy of the synovial membrane (black arrow) and joint capsule (white arrow) were evidence at week 1 p . i .

4 . 1 0 Photograph of the stifle joint. (a) Right stifle joint ; normal and 69 non-induced . (b) Left stifle jo int . Thickening of articu lar carti lage especial ly at the trochlear groove (TG) were evidence at week 3 p . i . Hypertrophy of the synovial membrane (black arrow) and jo int capsule (white arrow) were also observed.

4.11 Photograph of the stifle joint. (a) Right stifle joint; normal and 70 non-induced . (b) Left stifle jo int at week 4 p . i . showing normal articular cart i lage compared with (a) , however the synovial membrane (black a rrow) and fibrous capsule (white arrow) is sti l l swol len .

4.12 Photograph of the stifle joint. (a) Right stifle joint; normal and 7 1 non-induced. (b) Left stifle joi nt at week 5 p . i . showing normal looking articular carti lage (AC) but with s l ightly swollen soft tissue (arrow) .

5.1 Photomicrograph of the synovial membrane at week 1 p . i . The 92 arrow is showing the thickened intima layer (S) , which is three to four layers thicker. The border is i rregular and d iffusely ulcerated. Notice the marked vascula r congestion (bv) and oedema (0) . H&E x 1 00.

5.2 Photomicrograph of the synovia l membrane at week 1 p . i . I n 92 response to arthritis , the synovium prol iferates with vi l lous l i ke projections (arrow) . H&E x1 00.

5 .3 Photomicrograph of the synovia l membrane at week 2 p . i . 93 showing hyperplasia (H) of the subintima layer with mononuclear inflammatory cel ls (arrow) . H&E x 1 00

5.4 Photomicrograph of the synovial membrane at week 4 p . i . The 93 synovial subintima shows generalised and severe hyperp lasia (H) with the presence of lymphocytes (arrow) , indicating chronic synovitis . H&E x1 00

5 .5 Photomicrograph of the articular carti lage at week 1 p . i . 94 showing flaking and erosion (arrow) . The increased density from zone 1 (A) to tidemarks (T) is evidenced . H&E x1 00

XIX

5.6 Photomicrograph of the articular cartilage at week 2 p . i . 94 showing flaking and mi ld f ibr i l lat ion of the articular surface. H&E x40

5 .7 Photomicrograph of the articular carti lage at week 3 p. i . 95 showing reduced density between zone 1 (A) and tidemarks (T) . H&E x1 00

5.8 Photomicrograph of the articular cart i lage at week 5 p . i . The 95 big arrow is point ing at the superfic ia l fissures or laceration . There was also some clustening of the chondrocytes (smal l arrow) observed . H&E x 1 00

5.9 Electron micrograph showing the normal art icular cart i lage of 96 a dog. The perichondrium (P) has numerous depressions that can serve as reservoirs for synovial flu ids. The perichondrium (P) is folded , to show the col lagen fibres (F) , i n the chondrocyte layer. SEM x 330.

5. 1 0 Electron micrograph of the articular cart i lage with severe 96 changes on the surface (lesion score 3). The cart i lage shows severe damage with visible chondrocytes layer (C), observed on week 1 p . i . SEM x 1 , 1 00

5. 1 1 Electron micrograph of the articular carti lage with severe 97 lesions with score 4. The damage on the chondrocytes layer (C), observed on week 2 p . i . is severe . SEM x 2 ,200

5. 1 2 E lectron micrograph of the articular carti lage with moderate 97 lesions with the score of 2 . There a re moderate destruction (D) leading to erosion of the articular surface, observed on week 4 to 5 p . i . SEM x 1 ,900

5. 1 3 Electron micrograph showing the normal synovia l membrane 98 of the adipose type. The dome-shaped synoviocyte layer (S) , standing out wel l above the subintimal layer. SEM x750

5.14 Electron micrograph showing the normal synovial membrane 98 of the fibrous type, is folded and has a surface mat (M) of fibres . SEM x1 ,000

5. 1 5 Electron micrograph showing the normal synovial membrane 99 of the a reolar type. SEM x1 ,000

xx

%

Ilm

<

D BKL

et 81.

H&E

HA

IL-I

I LT-6

kg

mg/kg

MIA

m l

mm

NSA I Ds

OA

OCD

OS04

P

p . i .

PG

PGE2

PSGAG

SEM

TNF-a

LIST OF ABBREVIATIONS

percent

micrometer

Less than

Dewan 8andaraya Kuala Lumpur

And others (Latin: et al i i )

haematoxyl i n-eosin

Hyaluronic acid

i nterleukin I

i nterleukin-6

ki logram

mi l l igram perkilogram

Sodium monoiodoacetate

mi l i l itre

mi l imeter

non-steroidal anti-inflammatory d rugs

osteoarthritis

osteochondritis d issecans

osmium tetroxide

probabil ity

Post induction I post inoculation

proteoglycan

prostaglandin

Polysulphated Glycoaminoglycans

Scann ing electron m icroscopy

Tumor necrosis factor

XXI

1.1 General Introduction

CHAPTER 1

INTRODUCTION

Arthritis in a simple defin ition is inflammation of the joint. Osteoarthritis,

also known as degenerative joint d isease is not a single d isease or process , but

rather the cl in ical and pathological outcome of a range of disorders (Nuki , 1 999)

characterized by progressive deterioration of the articular carti lage, synovitis and

joint effusion (Mcl lwraith , 1 996) .

The purpose of joint is to support the greatest stabi l ity to the body during

weight bearing and motion. Painless and ful l range of jOint motion are needed

for normal ambulation and performance of daily l iving chores (Leach and Jacobs ,

1 990) . I nterruption of normal joint mechanics leads to painful osteoarthritis and

physical incapacity thereby reducing an ind ividual 's qual ity of l ife and increasing

the burden on others (Bennet, 1 990). Thus, diseases of joint are said to

constitute the greatest single cause of d isability encountered by the med ical

profession (Mc"wraith , 1 996) .

Osteoarthritis is one of the most frequently encountered joint diseases in

dogs (Bennet, 1 984) . Developmental diseases such as patel la luxation and

osteochondrosis of the femoral condyles, and traumatic .and degenerative

. diseases such as rupture of the cranial cruciate l igament or primary degenerative

joint d isease are seen frequently in small animal practices (Payne and

2

Constantinescu, 1993) . Although the cause of osteoarthritis varies , i n it ial

changes in many animals i nclude inflammation of the synovial membranes and

joint capsule without carti lage damage (Sherman et al. , 1 999) .

I n dogs and cats , osteoarthritis is not id iopathic or primary. It is usual ly

secondary to trauma, unstable joints, mal-al ignment or conformation defects , or

congenital conditions such as osteochondritis d issecans (OCD) and h ip

dysplacia (Payne and Constantinescu , 1 993). Thus , proper d iagnostic and

management of joint d isease depend on the understanding of basic anatomy

and physiology of the musculoskeletal system (Mcl lwraith , 1 996).

1 .2 Osteoarthritis Study

Osteoarthritis (OA) or degenerative joint d isease is a chronic d isease

i nvolving carti lage degeneration and pain (Simmons et al. , 1 999) . It is an

important orthopedic condition that affects d iarthrodia l joints and resu lts i n h igh

morbidity (Anderson et a/., 1 993) . The most common joint that is affected with

osteoarthritis is the stifle jo int . In dogs, it has been identified as a common joint

d isease (Sherman et aI . , 1999) , accounting for approximately 37% of a l l

lameness in th is species of an imal (Bennet, 1 980) . I n dogs of more than 1 -year

old , osteoarthritis may affect as many as 20% of the dog (Anderson et aI. , 1 993) .

Arthritis in humans and animals is characterised by jo int degeneration,

which is usual ly accompanied by intra-articular inflammation. Unti l recently,

most emphasis in a rthritis research has been focussed on intra-articular events