Path - Joints Flashcards
Components of synovial joints
Joint space - lines joint cavity & articulating bones w layer of cartilage
Articular cartilage - hyaline cartilage, 70-80% water
Synoviocytes - produce fluid for synovial fluid
Chondrocytes - cells within cartilage; collagen - structural proteins & glycans - non structural proteins
Morphologic features of articular cartilage
Hyaline cartilage
Chondrocytes : collagen & glycans
TM : tide marker, junction between articulate & calcified cartilage
Morphologic features of subchondral bone
Morphologic features of synovium
Traumatic joint injury
Example of traumatic joint injury
Arthrogryposis
Congenital joint contracture, infant animal is born with limbs and joints splayed in various directions due to lack of movement & joint configuration in the womb
Pathogenesis of arthrogryposis
Sporadic - random/unknown
Intrauterine viral infection
- akabane virus
- blue tongue virus (Culicoides)
- schmallenberg virus
Hereditary CNS disease
Toxins - lupine plants & poison hemlock
Pathogenesis of degenerative joint disease
Chronic, destructive disease of synovial joints
Common sequel to various forms of joint injury
Inciting causes of degenerative joint disease
Age
Conformational defects : hip dysplasia, patellar luxation, osteochrondrosis
Excessive wear/use : athletic animals
Joint inflammation : synovitis, arthritis
Complex path of DJD
Damage to Chondrocytes
Proteoglycan depletion = dehydration
Loss of normal articular cartilage viscosity
Progressive loss of cartilage due to normal biomechanial forces (movement)
Release of cytokine/GF = inflammation, 2nd response
Cartilage matrix degradation > repair
Eburnation
“Like ivory”
Degeneration/wear in subcondylar bone, whitening appearance & polishing
Fibrillation of cartilage
Fissure is damage or a tear in cartilage, fibrillation is the sub acute or chronic condition with multiple fissures present in cartilage
What DJD is common in horses?
Navicular syndrome
Degenerative arthropathy of navicular bone
Common in fore limbs or abnormal foot conformation
What animal is osteophytes commonly found w DJD?
Ankylosing spondylosis is commonly found in what animal?
Dogs
Intervertebral disc disease is common in w hat animal
Pathogenesis of infectious arthritis
Hematogenous = poly arthritis, multi joint
Common in young animals
Direct extension - due to penetrating wound or adjacent soft tissue infection
Prognosis & outcome depend on degree of cartilage damage
Infection elim before Cartilage damage -> normal function
Cartilage damage occurs -> DJD, synovial fibrosis
Common Infections that lead to arthritis in pigs
Strep suis, haemophilus parasuis, mycoplasma, Trueperella pyogenes, E. coli, erysiplothrix rhusipathiae
Common infections that lead to arthritis in cattle
Trueperella pyogenes, e. Coli, strep spp, histophilus somni, mycoplasma bovis, salmonella, borrelia burgdoferi
Common infections that could cause arthritis in sheep
Mycoplasma, strep, chlamydophilia, E. coli
Common infections that could cause arthritis in goats
Caprine arthritis-encephalitis virus
Common infections that could cause arthritis in horses
Actinbacillus equuli, strep, e Coli, salmonella, borrelia burgdoferi
Common infections that can cause arthritis in dogs
Borrelia burgdoferi
Pathogenesis of suppurative diskospondylitis
Purulent inflammation of intervertebral disks, brucella infection
Non-infectious erosive arthritis pathogenesis
Rheumatoid arthritis
Chronic immune mediated disease
Pannus formation - migration of inflammation over the articular cartilage
Non-infectious non-erosive arthritis
Systemic lupus erythematosus
Anti-nuclear antibody, anemia, thrombocytopenia, glomerulonphritis, dermatitis
Path of idiopathic poly arthritis
Concurrent with chronic disease
Path of primary joint neoplasia
Synovial cell sarcoma
From synovial lining cells, can occur in joints/tendon sheaths
Locally invasive & destructive, moderate to low distant metastatic potential
Path of articular/ periarticular histocytic sarcoma
Within or adjacent to joints (stifle, elbow)
More common than SCS in dogs
Distant metastasis more likely than SCS
