Arthritis and Osteochondrosis Flashcards
Define arthropathy
any joint disease
Define arthritis
inflammation within a joint
Define polyarthritis
inflammation in several joints simultaneously
Define osteophyte
bony projections that form at synovial or articular margins
Define enthesiophyte
bone projections that form at tendon/ligament attachment
What is a joint mouse?
mobile fragment within a joint
- loose osteophyte
- fragment of cartilage
Define -rrhaphy
to suture in place, or to close
Define imbrication
surgical tightening
Define -plasty
surgical repair or shaping of
Define ankylosis
spontaneous fusion of a joint
- end stage of joint disease
Define arthrodesis
surgical fusion of a joint
Define arthrotomy
incision of a joint
What is the cause of primary osteoarthritis?
Is it more common it dogs or cats?
- idiopathic
- more common in cats
What are the causes of secondary osteoarthritis?
- DJD
- developmental (OCD, dysplasia)
- acquired (trauma, neoplasia)
Describe the pathophysiology of osteoarthritis
- damage to articular cartilage: aberrant repair causes degradation
- altered subchondral bone metabolism
- periarticular osteophytosis
- synovial inflammation
What are the common radiographic signs seen with osteoarthritis?
- osteophytes
- effusion
- increased or decreased joint space
- soft tissue swelling
- subchondral sclerosis
What are the possible medical treatments of osteoarthritis?
- weight management
- exercise moderation
- physical therapy
- analgesics
- disease-modifying agents
- neutraceuticals
What is the mechanism of action of NSAIDs?
reduce pro-inflammatory mediators by inhibiting COX
What is the main mechanism of disease-modifying agents?
promote synthesis over breakdown of cartilage
What is the MOA and effects of glucosamine/chondroitin?
- stimulate proteoglycan synthesis of hyaline cartilage
- anti-inflammatory
What is the MOA of omega-3 fatty acids?
compete with arachidonic acid as a substrate for COX
- produce less pro-inflammatory mediators
What is the MOA and effects of avocado/soybean unsaponifiables?
- anti-inflammatory, anti-osteoarthritic
- decrease inflammatory mediators
- increase cartilage matrix synthesis
What is osteochondrosis?
defect in endochondrial ossification
Describe endochondrial ossification
- the process by which epiphyseal cartilage becomes bone
- starts from epiphyseal center of ossification
- travels outward in ossification wave
- anastomosis forms between perichondral plexus and epiphyseal bone supply
Describe the pathophysiology of osteochondrosis
- disruptions in anastomosis leads to cartilage necrosis
- necrosis blocks ossification wave
- cartilage thickens
What is osteochondrosis dissecans?
- a flap of cartilage is lifted from the articular surface
- necrotic cartilage induces repair
What is meant by “biphasic presentation” in regards to OCD?
- initially and in young animals, pain is due to inflammation
- later and in mature animals, pain is due to DJD
What are the predisposing factors for OCD?
- genetics/hereditary (not alone): males, large breeds
- high vitamin D/calcium
- high dietary energy
- trauma
What is the difference between microtrauma and macrotrauma?
micro - normal weight-bearing stress
macro - athletic, high impact stress
Which joints are more commonly affected by OCD?
shoulder - CdL humeral head
elbow - M humeral condyle
hock - M/L talar ride
stifle - M/L femoral condyle
What are the indications for conservative treatment of OCD?
- small lesion
- young patient
- clinically silent or mild lameness
- poor surgical outcome
What are the possible surgical treatments of OCD?
- fragment removal and subchondral bone debridement
- replacement of articular cartilage with fibrocartilage
- osteochrondral transplants
