Response of joint to injury, osteoarthritis

What is another term for a fibrous joint?

synarthroses

What is another term for a cartilaginous joint?

amphiarthroses

What is another term for a synovial joint?

diarthrodial

What are osteophytes?

bony lumps that grow around joints

What are enthesophyes?

a bony spur forming at a ligament or tendon insertion into bone

What are ankylosis?

fusion of a joint by bone or fibrous tissue

What is the synovial membranes primary response to injury?

undergo hypertrophy and hyperplasia thereby increasing their synthetic and phagocytic functions (villous proliferation), synovial blood vessels may proliferate secondary to inflammation producing a fibrovascular membrane (pannus)

What is the synovial membranes secondary response to injury?

joint capsule thickens due to proliferation of fibrous connective tissue; may have foci of mineralization and may see metaplasia of subsynovial connective tissue to form osteochondral nodules (osteophytes)

What is the synoviums response to inflammation?

chronic arthritis; proliferation and thickening of the inner synovial membrane which forms villi causing a velvety appearance

What is pannus?

fibrovascular and histiocytic tissue (granulation tissue) arising from synovial membrane spreads over the adjacent surfaces (articular cartilage), fibrous outer capsule will thicken and become more pronounced

What is the reaction to injury of articular cartilage?

limited response to injury, minimal capacity for repair/regeneration; aneural and avascular so injury to articular cartilage is not painful; sterile injury or infectious inflammation can cause cartilage degradation and necrosis

What is chondromalacia?

cartilage softening secondary to loss of proteoglycans

What is fibrillation?

loss of superficial cartilage (erosion) with fraying of collagen fibers

What is eburnation?

full thickness loss of articular cartilage (ulceration) with exposure of thickened and sclerotic subchondral bone; cartilage is missing and exposed subchondral bone has increased density

What is a joint mice? (trophus, tophaceous body)

fragments of cartilage break off articular surface and fall into joint cavity where it receives nutrients and survive, may grow and ossify

What is increased subchondral bone density/subchondral bone sclerosis?

if bone bears increased force it causes decreased resorption, increased formation

What is granulation tissue response?

produced if injury penetrates through tidemark into subchondral bone, bone formation begins and extends toward articular cartilage; but formation of reactive bone is only sufficient to fill the defect in bone

What is the fibrocartilage response to subchondral bone injury?

in addition to formation of reactive bone, may see formation of fibrocartilage that may incompletely fill cartilage defect

What are subchondral pseudocysts?

following deep cartilage injury that penetrate bone, granulation tissue is formed in subchondral bone, subchondral bone is resorbed to form a cavity frilled with myxomatous tissue and surrounding trabeculae become thick and produce a zone of sclerosis to form a pseudocyst

What are periarticular osteophytes?

develop in transitional zone of synovial membrane, forms osseous/cartilagenous nodules by direct ossification or by vascular invasion and endochondral ossification

What is another term for osteoarthritis? Can use these terms interchangeably.

degenerative joint disease

What is osteoarthritis?

destructive disease of synovial joint; primary DJD has no identifiable cause but secondary DJD has a known predisposing factor

What is the typical progression of OA/DJD?

chondromalacia followed by fibrillation, horizontal splits and joint mice, cartilage ulceration, eburnation, osteophyte formation

What are the early changes since with OA/DJD?

chondromalacia and fibrillation (erosion)

What are the late changes since with OA/DJD?

osteophytes, enthesophyte, eburnation, subchondral pseudocysts, ankylosis

What can happen to the OA/DJD process once a joint becomes irritated?

becomes a self-perpetuating problem due to the irritation of the roughened, irregular articular and synovial surfaces on each other

What is degenerative of intervertebral disks?

age-related phenomenon in many species seen mostly in chondrodystrophic breeds, chondroid metaplasia of the nucleus pulposus is followed by calcification during the first year of life; disc herniation usually occurs dorsally

What happens to the nucleus pulposus with IVDD?

loss of water and proteoglycans, increase in collagen content

What happens to the annulus fibrosus with IVDD?

gradual degeneration and weakening

What is hansen type 1 IVDD?

complete rupture of the annulus fibrosus with extrusion of nucleus pulposus into the vertebral canal (chondrodystrophic dogs)

What is hansen type 2 IVDD?

prolapse of the nucleus pulposus secondary to partial rupture of the annulus fibrosis (geriatric)

What is type 3 IVDD?

high-velocity low volume disc disease or acute non-compressive nucleus pulposus extrusion. traumatic extrusion of the normal nucleus pulposus causes non-compressive contusion injury to the spinal cord; usually due to trauma

What are the spinal cord lesions due to in IVDD?

direct pressure on the cord, pressure on the afferent veins and arterioles causing cord ischemia, inflammation invoked by the degenerative disk material in the spinal canal

What are the cartilaginous joint arthropathies?

fibrocartilaginous embolism and spondylosis deformans

What is fibrocartilaginous embolism?

related to IVDD causes herniation of disk material into vasculature, extruded nucleus pulposus enters the arterial system where it causes infarctions of the spinal cord arterioles further down arterial stream

What is spondylosis deformans?

osteoarthritis of joints between vertebral bodies characterized by osteophytes that grow toward each other and eventually bridge the intervertebral space; generally along the ventral and lateral sides; protrusion of intervertebral disk ventrally is accompanied by degeneration/tearing of fibers of annulus fibrosus from their attachments at margins of vertebral body

Why is spondylosis deformans important in aged dairy bulls?

used for semen collection but their usefulness ends due to severe pail development