Arthritis and OCD Objectives Flashcards
Any joint disease is known as an
arthropathy
Broad term for degenerative and other diseases of the joint
Arthrosis
Inflammation within a joint
Arthritis
Inflammation in several joints simultaneously
Polyarthritis
Term for surgical closure of the joint capsule
Capsulorrhapy
Surgical tightening of fascia, joint capsule, tendon
or
surgical pleating and folding of tissue to realign organs and provide
extra support,e.g. chronically stretched joint capsule.
Imbrication
Surgical repair or shaping of a joint
Arthroplasty
a bony outgrowth associated with the degeneration of cartilage at joints
Osteophyte
abnormal bony projections at the attachment of a tendon or ligament
Enthesophytes
(They are not to be confused with osteophytes, which are abnormal bony projections in joint spaces)
a loose fragment (as of cartilage) within a synovial space
Joint mouse
abnormal stiffening and immobility of a joint due to fusion of the bones
or
spontaneous fusion of a joint (when osteophytes come together)
as an end result of chronic joint disease
Ankylosis
Surgical fusion of a joint
Arthrodesis
(better than ankylosis which occurs on its own)
Incision into a joint
arthrotomy
What are the 3 categories of joints?
Synovial
Cartilagenous
Fibrous
What category of joints are being referred to when talking
about arthritis?
Synovial joints
What is the difference between inflammatory and non-inflammatory
arthritis?
Inflammatory means that the primary cause of the arthritis is inflammation
Non-inflammatory means that inflammation is a secondary effect of the primary cause of the arthritis
What are the primary sub‐classifications of inflammatory arthritis?
-
Infectious
- bacterial (septic)
- fungal
- mycoplasmal
-
Non-Infectious (Immune-mediated)
- Erosive (rheumatoid)
- Non-erosive
What are the primary sub‐classifications of NON - inflammatory arthritis?
- Primary (Idiopathic) Osteoarthritis
-
Secondary Osteoarthritis (DJD)
- Developmental (OCD, Hip Dysplasia)
- Acquired (trauma, neoplasia)
Which is more common (primary vs. secondary arthritis)
in dogs? In cats?
Primary is more common in CATS
Secondary is more common in DOGS
How do you differentiate between inflammatory and non-inflammatory
arthritis?
JOINT TAP!
What are the radiographic findings associated with arthritis?
Osteophytes
Soft tissue swelling
Joint inflammation or effusion
Subchondral sclerosis
Increased or decreased joint space
What are the limitations of radiographs for diagnosis of arthritis?
Rads are highly specific, but minimally sensitive for diagnosis of arthritis
If you don’t see it, you CANNOT say for sure it is not there,
especially in the elbow
What are the 6 categories of nonsurgical treatment for osteoarthritis?
Weight management
Exercise moderation
Physical rehabilitation
Symptom-modifying agents (analgesics)
Disease-modifying agents (reparatives)
Neutraceuticals (food or food products that provide medical benefits)
What is the most effective nonsurgical treatment for osteoarthritis?
WEIGHT MANAGEMENT
What is the MOA of NSAIDs?
Reduce pro-inflammatory mediators by inhibiting cyclooxygenase
(COX-1 Inhibition)
Why should you never give cats NSAIDs and what do you prescribe
for analgesia instead?
Cats are poor at glucoronidation (in the liver) which is how NSAIDs are broken down.
Give Onsior (Robenacoxib) instead - metabolized by the kidney
What is absolutely contraindicated if treating an animals with NSAIDs?
STEROIDS!
What is the general mechanism of action for reparatives?
To promote synthesis over breakdown or by
providing articular cartilage or fluid building blocks
What is the MOA for the following neutraceutical?
Glucosamine/Chondroitin
(Cosequin)
Stimulate proteoglycan synthesis of
hyaline cartilage matrix in vitro
What is the MOA for the following neutraceutical?
Omega 3 Fatty Acids
(EPA, DHA)
Compete with arachidonic acid as a substrate for COX
Results in production of less proinflammatory mediators
(decreased need for NSAIDs)
Basically, Omega-3 sorostitutes are whores because they love to compete for some COX
What is the MOA for the following neutraceutical?
Avocado and Soybean Unsaponifiables (ASU)
(Dasuquin)
Decrease inflammatory mediators and
increase cartilage matrix synthesis
What are the common side effects of NSAIDs?
For COX-1 inhibitors: GI and Kidney side effects
For COX-2 selective drugs: GI, Kidney, and Liver side effects
What is a side effect to be cautious of when using
Avocado and Soybean Unsaponifiables (ASU)?
Has induced arthritis in some animals!
What is the level of EBM support for reparatives
like PS-GAG and PPS?
GOOD EBM support
EBM for PS-GAG is best
What is the level of EBM support for Glucosamine/Chondroitin?
EBM states efficacy is uncertain, but it is safe
What is the level of EBM support for Omega-3 Fatty Acids?
GOOD EBM for Omega-3’s
(and rarely cause GI probs)
What is the level of EBM support for weight management?
Good to EXCELLENT EBM support
What is a salvage procedure?
A procedure in which the goal is to
preserve life/limb function,
but there is NO ATTEMPT to cure or fix the problem
(in this case, the cause of DJD)
What are the differences between joint replacement and partial excision arthroplasty in general terms?
A Joint Replacement Arthroplasty is a surgical procedure in which parts of an arthritic or damaged joint are removed and replaced with a prosthesis
A Partial Excision Arthroplasty is where the joint is remodeled but nothing is removed
What is the difference between ankylosis and arthrodesis?
Ankylosis is the body’s attempt to stabilize/fix a joint by growing bony osteophytes which eventually fuse together.
Arthrodesis the surgical method of doing the same thing, usually done to ameliorate the pain caused by the arthritic joint.
What are the the principles of arthrodesis?
Complete removal of ALL articular cartilage
Cancellous bone graft
Rigid fixation at standing angle (usually DCP)
What are the guidelines for postoperative management of arthrodesis?
Coaptation for 6 - 8 weeks
Activity restriction until bony fusion
Prolonged healing for 3 months minimum
What is the expected effect of arthrodesis of a given joint in general terms?
For high motion joints: “Peg Leg” gait
For low motion joints: Minimal effect on gait
Define osteochondrosis
DEFECT IN ENDOCHONDRAL OSSIFICATION
(self-limiting developmental derangement of normal bone growth, primarily involving the centers of ossification in the epiphysis. [1, 2] It usually begins in childhood as a degenerative or necrotic condition. Bydefinition, osteochondrosis is an aseptic ischemic necrosis.)
Describe the basic pattern of long bone growth
Starts from epiphyseael center of ossification→
Travels outward in an “ossification wave”→
Anastomoses form: perichondral plexus and epiphyseal bone supply
_____% of long bone growth occurs at the physis
80%
Endochondral ossification occurs at the ______
epiphysis
Endochondral ossification is usually complete by
_____ months of age
6 months
The epiphysis contributes _____% of bone growth
20%
An error or interruption in the anastomoses process leads to
_____ epiphyseal cartilage due to
cartilage ______ downstream
thicker
necrosis
Describe the pathophysiology of osteochondrosis
Disruptions in anastomoses→ cartilage necrosis downstream→
cartilage cannot ossify→ thickened cartilage→
acts as a “stress riser” (rising from inside the bone to the surface)→
necrotic cleft between cartilage and bone→
focused stress over cleft→
fracture of cartilage and defect in joint surface
How does a fissure between the thickened cartilage and subchondral bone trigger degenerative joint disease?
Fissure/fractured cartilage causes a defect in the joint surface
which accelerates DJD
What does the term
“multifactorial” mean when applied to the etiology of OCD?
Need both genetic and non-genetic factors for OCD to present:
- Genetics:
- Dogs, male, large/giant breeds
- Non-Genetic Factors:
- High Ca/Vit D (promote errors in endochondral ossification)
- Energy
- Trauma
What is the gender and breed disposition of OCD?
Males, large/giant breed dogs, Great Danes
What is the significance of heritability in OCD?
Heritability is 10 - 45%, so should NOT BREED these animals
What is the relationship between
dietary calcium and vitamin D levels and OCD?
HIGH Ca/Vit D promotes errors in endochondral ossification
How does dietary energy relate to the development of OCD?
Dietary energy:
Promotes development of bone and muscle
Increases stress on developing cartilage with RAPID growth
What is the difference between
microtrauma and macrotrauma as related to OCD?
Microtrauma= normal weightbearing stress
But in OCD, abnormal weakened cartilage is more prone to injury, and lesions occur even with normal stresses
Macrotrauma= athletic, high impact stress
In OCD, may cause subclinical to become clinical
What does the phrase “developmental orthopedic disease” signify?
It means that the disease is heritable!
What is a “biphasic age distribution” (referring to age at presentation)
and why it is present with OCD?
Means that two age groups can typically present with the disease.
In OCD, can present in young animals due to inflammatory arthritis
or in older animals due to secondary DJD
Describe a typical patient with OCD
(this applies to OCD manifesting in all joints)
Male, large or giant breed dog
Either 4 - 8 months or middle-aged to old
Limb lameness, pain on joint manipulation, bilateral issues
What are the locations where OCD is commonly found in dogs?
Shoulder- humeral head (caudolateral)
Elbow- humeral condyle (medial)
Hock (Ankle)- talar ridge (medial or lateral)
Stifle- femoral condyle (medial or lateral)
Describe the radiographic findings compatible with OCD
For the shoulder- flattened caudal humeral head =OCD
May see joint mouse (loose cartilage flap)
What are the potential preventive measures recommended with OCD?
Energy, calcium, and vitamin D restriction
Exercise restriction
Describe a patient for which conservative treatment of OCD
might be acceptable
Small lesion
Young patient (<6m)
Clinically silent, or only mild lameness
Poor surgical outcome
List the components of conservative management for OCD
Energy, calcium, and vitamin D restriction
Exercise restriction
Weight control
NSAIDs
Describe the most common surgical treatment for OCD and the
difference in the type of cartilage that forms as the defect heals
Sx = Fragment removal and subchondral bone debridement
Articular cartilage is replaced by fibrocartilage
