Diagnostic and Treatment of Joint Diseases of Small Animals

1

Diagnostic and Treatment of Joint Diseases of Small Animals

UpdatesClinical Management

2

Introduction

Increase of the frequence of joint diseases in dogs and cats due to:

increase of life expectancymore medium - large breedsmore obese animalsIncrease of animal of predisposed breeds

Difficult to accurately diagnose

3

Structure of Joint

Synovial fluidfeeds the cartilage

+ lubricationArticular Cartilage« shock absorption »

Subchondral plate:« support »

Joint Capsule:ligament-likestructure

+ synovialmembrane

4

The Healthy Cartilage

Matrix: shock absorption80% water12% collagen2% proteoglycansother substances

Chondrocytes:synthesis of proteoglycanssecretion of catabolic enzymes

=> regulation system:balance synthesis / degradation

Sources: McIlwraith, C.W., Trotter, G.W. (1996): Joint disease in the horse., W.B. Saunders, Philadelphia, USA.

5

Structure of Cartilage Matrix

6

Physiology of Cartilage

Not irrigated by blood vessels=> specific nutrition system: « pumping »

DEPRESSIONaspiration of the synovial

fluid

COMPRESSIONrejection of waste in the

synovial fluid

WASTE NUTRIMENTS

7

Inflammatory Joint Diseases

Very numerous:more than 300 are listed in the litterature

Varied causes:immune mediated factorsmicrobial infectionsecondary effect of trauma

8

Inflammatory Joint Diseases

Immune mediated polyarthritis

Picture: Masahiro Okumura..

9

Non-Inflammatory Joint Diseases

Degeneration of joint structures, like cartilage:

OSTEOARTHRITIS

OSTEOARTICULAR DYSPLASIA

10

General Pathogenic Process

In case of joint disease:

Modification of cartilage matrix homeostasis

=> lowering of viscoelasticity

=> increase of frictions

This leads to degenerative disease= osteoarthritis (OA) = degenerative joint disease (DJD)

11

OA Pathogenic Process: Phase 1

Over-pressureon normal cartilage:

luxationunstability of the jointdysplasiaoverweight

OR Normal pressureon un-normal cartilage

tumoral processold cartilagegenetic malformationnutritionnal troubles

12

OA Pathogenic Process: Phase 2Hyperpressure

Increase ofMetalloproteases

Decreaseof synthesis

Release of cartilage fragments

PgE2

Inflammation

Activation of chondrocytes

Destructionof cartilage Matrix

PAIN

13

OA Pathogenic Process: Phase 3Hyperpressure

Increase ofMetalloproteasesDecrease

of synthesis


Inflammation

Activation of chondrocytesIL 1 beta

Activation of synoviocytes


IL 1 betaIL6TNF alpha

PgE2

Synthesisof proteases

+m

acro

phag

es

PAIN

14

OA Pathogenic Process: Results

Fibrosis of the capsuleOsteophytesBone remodelling

Healthy OA

Biochemicaland MechanicalVicious Circle

15

General Physical ExaminationInterview of the owner:

Sudden / slow onset of the disease ?Date of apparition and evolution, cyclic or permanent ?General mobility of the animal + specific motion of the legs ?

Demeanour

Examination of the Gait

Neurological tests (to exclude neurological etiology)

16

Examination of Lameness

Focus on the attitude of the legsAnimal walking toward you / away from you

Permanent / intermitent lameness ?

Strides of each foot ?

Movements of joint under loading ?

17

Orthopaedic Evaluation (1)

Animal standing still:

Posture ?Muscle atrophy ?Muscular reaction ?Pain along the spine, at the neck or the back ?

18


Palpation (1):identifiate painful bones, ligaments, tendons

Abnormalities ? Displacements ?Joints with fibrosis ?Pain ?In-stability ?

19


Palpation (2):

Restriction in the motion of any leg / joint ?Crepitus ?Condition of soft tissues around joint ?Swelling ?

20


Palpation of the joint of the elbow


21


Palpation of the joint of the elbow


22


Palpation of the joint of the hip


23


Biodynamic tests:

To carry out on a sedated / anesthesied animal

To evaluate stability of the joint

Cranial drawer signOrtolani signBarden sign

24


Biodynamic tests:

Cranial drawer sign

anterior cruciate ligament rupture of the knee joint

Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.

25


Biodynamic tests:

Ortolani sign

stability of hip joint having dyspasia


26

Diagnostic Imaging

Changes in joint structure


27

Diagnostic Imaging: X-Ray

Time gap between the begining of the disease and the stage when the lesions are detectable by radiography

All lesions may not be all related to the present disease

28

Diagnostic Imaging: X-RayOA of elbow joint

Fragmented medial coronoid process

Remodeling of the subchondral bone


29

Diagnostic Imaging: X-RayOA of hip joint


30

Diagnostic Imaging: X-RayOA of knee joint


31

Diagnostic Imaging: Arthroscopy

Interest:

direct observation of ligaments, tendons, synovial membrane, articular cartilage

biopsy of synovial membrane

excising, removing fragments

32


Arthroscopy of the Elbow


33


Fragmented coronoid process of ulna

Erosion ofcartilage

Hyperplasiaof synovial membrane

Coronoidprocess

Fragmentedmedialsurfaceof ulna

HUMERUS

RADIUS


34


Fragmented coronoid process of ulna

=> Inflammation of thesynovial membrane

Biceps tendon inthe shoulder joint =>

35

Diagnostic Imaging: Tomography

X-Ray CT:excellent for detecting calcification

X-Ray CT 3DMRI:

can show images of soft tissues like cartilage and tendon

Limits:costdeep sedation / anesthesia requiredresolution of the images obtained

36


X-Ray CT:Fragmented coronoid process of ulna


37


X-Ray CT 3D:Fragmented coronoid process of ulna

HUMERUS

ULNA

RADIUSULNA

HUMERUS



38


Ultrasonography:

useful in detection of lesions of biceps and ligaments

not a practical examination for joints because of a very small acoustic window in this particular area

39

Tests on Synovial Fluid

Interesting to detect and evaluate:infectionsneoplasiainflammation

Puncturing:a perfect aseptia is required22-25G needle2ml syringe

40


Elements to analyse:amount of fluidappearancecytological analysis

presence of PNN => inflammationPNN morphology: immune disease vs. infection

protein contentbacteriological culture test

41


Amount of fluidAppearance


42

Treatment Strategy

Conservative therapyremove the cause of the diseasecontrol pain and inflammationprotect the damaged cartilage

=> a Combined Drug Therapy is needed

Surgical treatmentoften last resort

when the control of painbecomes impossible

43

Conservative Therapy

Supportive treatment:

Mild exercice is needed every day:to maintain range of motion of jointto strengthen soft tissues around the jointto enhance the metabolic activity of cartilage

Weight controlto decrease the over-pressure on the cartilage

44

Conservative Therapy

Purposes of drug therapy:

Control of Pain, on short and long term for animal welfare & to support cartilage physiologyControl of InflammationModify the cartilage Matrix Metabolism

Long term treatment => drugs with minimal side effects are required

45

Conservative Therapy: Drugs (1)

Available drugs:NSAIDs: oral & injectableDMOAs: oral & injectable

(Disease-modifying osteoarthritis agents)

Steroids: oral & injectableMorphinics: oral & injectableLocal anesthetics

46


All drugs are complementary:

DrugsReduction of

Pain Reduction of

InflammationProtection

of cartilageAdverse effects

NSAIDs ++, short term

++, short term

0/+ +

DMOAs ++, long term

++, long term

+++ 0

Steroids ++, temporary

+++ - - - ++

Morphinics ++ 0 0 + Local

anesthetics +++,

short action0 0 0

47

Conservative Therapy: Drugs (3)Hyperpressure

Increase ofMetalloproteases

Increase ofsynthesis


Inflammation

Activation of chondrocytesIL 1 beta

Activation of synoviocytes


IL 1 betaIL6TNF alpha

PgE2

Synthesisof proteases

CS

CS

NSAID

NSAID

NSAID

NSAIDCS

CS

CS

CS

PAIN

MorphinicsLocal Anesth.

+macrophages

Steroids

Steroids

CS

CS = Chondroitin Sulfate (DMOA)

48


Drug Strategy:

Common case: NSAID (short-medium term)

+ DMOA (from the beginning- long term effect)

If severe inflammation: + Steroids (short term)

If severe pain still present after NSAIDs:+ Local anesthetics+ Morphinics

49


Available DMOAs:

Drugs Pro Cons Recommendations

Chondroitine Sulfate

- Anti-inflammatory + chondroprotective effect

- The predominant proteoglycan in the matrix

- Carry-over effect

- Needs 2 weeks to show effects by oral route

- Highly degradated in the digestive tract

- As soon as the begining of the treatment, in

combination with pain killers - Long term management

Hyaluronic acid - Lubrication role when

injected in the joint

- Difficult management of injections on the long

term

- Injection at the begining of the treatment

Glucosamine

- Lubrication role when injected in the joint

- Resistant to digestive enzymes

- More structural than anti-inflammatory effect

- No direct study in small animals

- Idem CS - May be completed with NSAIDs on the long term

50

Surgical Treatment

Arthrodesiscommon procedure

Replacement arthroplastyuse of artificial materials=>use for the hip joint of large dogs only

Excisional arthroplastyEasier, but functions reduced after surgery(except for the hip)

51

Surgical Treatment: Arhrodesis

Articulardisintegration


52

Conclusion

Joint diseases concern welfare and quality of live

Easy and objective methods for diagnosisTreat the underlying diseasesRestore joint functionCombined therapy is needed for treatment, in addition to animal welfare & quality of life

Documents

Diagnostic and Treatment of Joint Diseases of Small Animals