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Diagnostic and Treatment of Joint Diseases of Small Animals
UpdatesClinical Management
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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
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Structure of Joint
Synovial fluidfeeds the cartilage
+ lubricationArticular Cartilage« shock absorption »
Subchondral plate:« support »
Joint Capsule:ligament-likestructure
+ synovialmembrane
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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.
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Structure of Cartilage Matrix
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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
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Inflammatory Joint Diseases
Very numerous:more than 300 are listed in the litterature
Varied causes:immune mediated factorsmicrobial infectionsecondary effect of trauma
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Inflammatory Joint Diseases
Immune mediated polyarthritis
Picture: Masahiro Okumura..
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Non-Inflammatory Joint Diseases
Degeneration of joint structures, like cartilage:
OSTEOARTHRITIS
OSTEOARTICULAR DYSPLASIA
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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)
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OA Pathogenic Process: Phase 1
Over-pressureon normal cartilage:
luxationunstability of the jointdysplasiaoverweight
OR Normal pressureon un-normal cartilage
tumoral processold cartilagegenetic malformationnutritionnal troubles
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OA Pathogenic Process: Phase 2Hyperpressure
Increase ofMetalloproteases
Decreaseof synthesis
Release of cartilage fragments
PgE2
Inflammation
Activation of chondrocytes
Destructionof cartilage Matrix
PAIN
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OA Pathogenic Process: Phase 3Hyperpressure
Increase ofMetalloproteasesDecrease
of synthesis
Release of cartilage fragments
Inflammation
Activation of chondrocytesIL 1 beta
Activation of synoviocytes
Destructionof cartilage Matrix
IL 1 betaIL6TNF alpha
PgE2
Synthesisof proteases
+m
acro
phag
es
PAIN
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OA Pathogenic Process: Results
Fibrosis of the capsuleOsteophytesBone remodelling
Healthy OA
Biochemicaland MechanicalVicious Circle
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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)
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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 ?
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Orthopaedic Evaluation (1)
Animal standing still:
Posture ?Muscle atrophy ?Muscular reaction ?Pain along the spine, at the neck or the back ?
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Orthopaedic Evaluation (2)
Palpation (1):identifiate painful bones, ligaments, tendons
Abnormalities ? Displacements ?Joints with fibrosis ?Pain ?In-stability ?
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Orthopaedic Evaluation (3)
Palpation (2):
Restriction in the motion of any leg / joint ?Crepitus ?Condition of soft tissues around joint ?Swelling ?
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Orthopaedic Evaluation (4)
Palpation of the joint of the elbow
Picture: Masahiro Okumura..
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Orthopaedic Evaluation (5)
Palpation of the joint of the elbow
Picture: Masahiro Okumura..
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Orthopaedic Evaluation (6)
Palpation of the joint of the hip
Picture: Masahiro Okumura..
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Orthopaedic Evaluation (7)
Biodynamic tests:
To carry out on a sedated / anesthesied animal
To evaluate stability of the joint
Cranial drawer signOrtolani signBarden sign
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Orthopaedic Evaluation (8)
Biodynamic tests:
Cranial drawer sign
anterior cruciate ligament rupture of the knee joint
Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.
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Orthopaedic Evaluation (9)
Biodynamic tests:
Ortolani sign
stability of hip joint having dyspasia
Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.
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Diagnostic Imaging
Changes in joint structure
Sources: McIlwraith, C.W., Trotter, G.W. (1996): Joint disease in the horse., W.B. Saunders, Philadelphia, USA.
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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
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Diagnostic Imaging: X-RayOA of elbow joint
Fragmented medial coronoid process
Remodeling of the subchondral bone
Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.
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Diagnostic Imaging: X-RayOA of hip joint
Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.
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Diagnostic Imaging: X-RayOA of knee joint
Source: Whittick, W.G. (1990): canine Orthopedics. Lea & Febiger, Philadehphia, USA.
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Diagnostic Imaging: Arthroscopy
Interest:
direct observation of ligaments, tendons, synovial membrane, articular cartilage
biopsy of synovial membrane
excising, removing fragments
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Diagnostic Imaging: Arthroscopy
Arthroscopy of the Elbow
Picture: Masahiro Okumura..
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Diagnostic Imaging: Arthroscopy
Fragmented coronoid process of ulna
Erosion ofcartilage
Hyperplasiaof synovial membrane
Coronoidprocess
Fragmentedmedialsurfaceof ulna
HUMERUS
RADIUS
Sources: McIlwraith, C.W., Trotter, G.W. (1996): Joint disease in the horse., W.B. Saunders, Philadelphia, USA.
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Diagnostic Imaging: Arthroscopy
Fragmented coronoid process of ulna
=> Inflammation of thesynovial membrane
Biceps tendon inthe shoulder joint =>
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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
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Diagnostic Imaging: Tomography
X-Ray CT:Fragmented coronoid process of ulna
Picture: Masahiro Okumura..
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Diagnostic Imaging: Tomography
X-Ray CT 3D:Fragmented coronoid process of ulna
HUMERUS
ULNA
RADIUSULNA
HUMERUS
Picture: Masahiro Okumura..
Picture: Masahiro Okumura..
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Diagnostic Imaging: Tomography
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
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Tests on Synovial Fluid
Interesting to detect and evaluate:infectionsneoplasiainflammation
Puncturing:a perfect aseptia is required22-25G needle2ml syringe
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Tests on Synovial Fluid
Elements to analyse:amount of fluidappearancecytological analysis
presence of PNN => inflammationPNN morphology: immune disease vs. infection
protein contentbacteriological culture test
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Tests on Synovial Fluid
Amount of fluidAppearance
Picture: Masahiro Okumura..
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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
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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
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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
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Conservative Therapy: Drugs (1)
Available drugs:NSAIDs: oral & injectableDMOAs: oral & injectable
(Disease-modifying osteoarthritis agents)
Steroids: oral & injectableMorphinics: oral & injectableLocal anesthetics
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Conservative Therapy: Drugs (2)
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
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Conservative Therapy: Drugs (3)Hyperpressure
Increase ofMetalloproteases
Increase ofsynthesis
Release of cartilage fragments
Inflammation
Activation of chondrocytesIL 1 beta
Activation of synoviocytes
Destructionof cartilage Matrix
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)
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Conservative Therapy: Drugs (4)
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
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Conservative Therapy: Drugs (5)
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
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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)
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Surgical Treatment: Arhrodesis
Articulardisintegration
Picture: Masahiro Okumura..
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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