Lecture 17: Bone Pathology II Flashcards
What wrong and what cause
congenital cortical hyperosteosis (diaphyseal dysplasia)
Cause: autosomal recessive hereditary disease of newborn pigs
what are the signs of congenital cortical hyperosteosis
thickening of 1 or both forelimbs
Congenital cortical hyperostosis involved abnormal __ formation involving major lone bones. __ and __ bones most severely affected
periosteal bone formation, radius and ulna
piglets with congenital cortical hyperostosis are either __ or __ within first few days of life
stillborn, die
what are chondrodysplasias
primary lesions in the growth cartilage on physis and articular epiphyseal cartilage complex
what is disproportionate dwarfism and what is cause
chondrodysplasia that results in short legs with normal sized heads
Cause: mutation in fibroblast growth factor 4 (FGF4) that cause inappropriate activate of one or more FGFR (3) causing downregulation of chondrocytes proliferation
what is primordial dwarfism
limb length is proportional to head, caused by endocrine disorder- pituitary dwarfism or malnutrition
FGFR3 receptor is expressed by __ and __, not __ and acts as a __ chondrocyte proliferation
resting and proliferating chondrocytes, not hypertrophic chondrocytes, acts as inhibitor of chondrocyte proliferation and terminal differentiation
what is spider lamb syndrome and cause
chondrodyplasia in sheep
Point mutation in FGFR3, removing FGFR3 induced inhibition of chondrocyte proliferation
what breeds are affected by spider lamb syndrome
suffolks and Hampshire
what is pathogenesis of spider lamb syndrome
point mutation in FGFR3–> decreased FGFR3 inhibition of chondrocytes entering hypertrophic phase—> increased length of long bones and presence of multiple secondary ossification centers in epiphyses—> variation in shape, size and orientation of bones
what wrong and cause
spider lamb sheep syndrome
Notice multiple secondary ossification centers
Cause: point mutation in FGFR3
what are osteochondroses
lesions in growth cartilage of young animals, characterized by focal or multifocal failure or delay of endochondral ossification
what is osteochondrosis latent
well demarcated area of necrosis in epiphyseal cartilaged centered on necrotic blood vessels (only visible microscopically)
what is osteochondrosis manifest a
retained necrotic epiphyseal cartilage that is appreciated grossly
what is OCD
lesion at articular epiphyseal cartilage complex that forms a cleft in the necrotic cartilage with subsequent fracture of articular cartilage resulting in cartilaginous or osteochondral flap
identify the different osteochondroses seen in 1-3
- Osteochondrosis latent
- Osteochondrosis manifests
- Osteochondrosis dissects
what are joint mice
cartilage or osteochondral flaps that have fractured/detached from articular surface
how do bone cysts form
osteochondrosis—> necrosis—> cavitation—> subchondral cyst
what wrong
OCD with joint mice
what is rickets and osteomalacia and cause
failure of mineralization with subsequent bone deformities and fractures
Cause: vitamin D or phosphorus deficiency
what is pathogenesis of rickets and osteomalacia
vitamin D deficiency—> hypocalcemia—> stimulates PTH—> renal phosphorus loss enhanced further reducing deposition of calcium in bone—> causing bone pain, pathological fractures, and deformities such as scoliosis and kyphosis
what animals get rickets and what does it affect
growing animals, failure of endochondral ossification, affects bones and epiphyseal cartilage
who gets osteomalacia and what does it affect
adults, soft bone- affects bone only
how would you characterize this lesion, what wrong and what cause
Rachistic rosary- due to rickets- irregular growth plates due to failure of endochondral ossification
what could have caused this in 1yr old steer
Rickets- phosphorus or vitamin D deficiency- pale blue is cartilage extending into bone
what are some causes of fibrous osteodystrophy
- Primary parathyroid adenoma, hyperplasia, carcinoma
- Secondary hyperparathyroidism- renal or nutritional
- Pseudo hyperparathyroidism
Fibrous osteodystrophy is characterized by
widespread osteoclastic resorption of bone and replacement by primitive fibro-osseous tissue resulting in weakened bones
how does increased PTH, renal disease and nutritional deficiency of ca2+ lead to fibrous osteodystrophy/ pathogenesis
stimulation of osteogenic and osteoclast bone resorption—> decrease bone mineralization and replacement by fibro-osseus CT—> weakened bone structure
what could have caused this swelling of mandible and maxilla
fibrous osteodystrophy—> osteoclast activity—> resorption of bone and replaced by fibro-osseous tissue
what is osteitis
inflammation of bone
what is periostitis
inflammation of bone involving periosteum
what is osteomyelitis
inflammation of bone with involvement of medullary cavity
what hematogenous bacteria can cause inflammation of bone
T. Pyogenes, strep, staph, salmonella, E. Coli
what fungi can cause inflammation of bone
C. Immitis and blastomyces dermatidis
what viruses can cause inflammation of bone
swine fever, canine infectious hepatitis (adenoviruses), distemper virus, FeLV
what wrong in these photos
Suppurative Osteomyelitis, physitis
What wrong here
Hypertrophic osteodystrophy (metaphyseal osteopathy)= double physis lines
what is cause of hypertrophic osteodystrophy
idiopathic inflammatory disease- non-infectious
Define exostosis
nodular benign bon growth projecting outward from surface of a bone
what is enostosis
bony growth within medullary cavity, originating in cortical-endosteal surface
what is an ethesophyte
calcification of a tendon or a ligament at its point of insertion
what is hyperostosis
increased diameter of bone and implies uniform thickening on periosteal surface rather than modularity
what wrong
cartilaginous exostosis (osteochondroma)
what are cartilaginous exostosis (osteochondroma)
defect in skeletal development that results in eccentric masses located adjacent to epiphyses
what wrong
Cartilaginous exostosis (osteochondroma)
what wrong
hypertrophic osteopathy
what is hypertrophic osteopathy and what is it associated with
bilateral periosteal new bone formation in diaphyseal region
Occurs secondary to primary lesion- intrathoracic neoplasia/inflammation
what is one theory on how intrathoracic masses can cause hypertrophic osteopathy
impulses originating in the thoracic lesion travel via the vagus nerve to the brainstem—> initiate reflex vasodilation in the limbs—> hypertrophic osteopathy
what wrong
chondrosarcoma
what wrong
osteosarcoma
what wrong
Secondary neoplasm of bone
Lung metastatic osteosarcoma
what are the most common sites of bone metastatic neoplasia in dogs and what tumor is most common
rib shafts, vertebral bodies, humeral and femoral metaphysis
Most often carcinomas
what is an infraction fracture
fracture without external deformation to cortex
what is an avulsed fracture
caused by traction of a ligament at its insertion onto bone
what is a green stick fracture
one cortex of bone is broken and other is bent
what type of fracture is this
avulsed
what type of fracture is this
green stick
describe the process of fracture repair occurring in body
- Macrophages, platelets, proliferating osteogenic tissue at site of fracture produce growth factors that stimulate proliferation of repair tissue/woven bone
- Undifferentiated mesenchymal cells penetrate and form granulation tissue
- Granulation tissue outcome of cartilage and bone metaplasia
- Primary callus (meshwork of woven bone) forms. Secondary callus forms when woven bone is replaced by lamellar bone
when Blood supply is less than optimal in fracture healing __will form
hyaline cartilage
when blood supply is anoxic during fracture healing __ will occur
necrosis
instability in fracture healing leading to mechanical tension and compression can cause development of ___ if excessive movement happens
fibrous CT
what happens if metallic implant too large for fracture repair
deprive bone from normal mechanical forces and causes disuse atrophy
how can intramedullary devices affect fracture healing
damage blood supply
what is arthrogryposis and what is pathogenesis
congenital contracture of joints
Damage to CNS (akabane virus and bluetongue), hereditary or fetal paralysis caused by maternal intoxication with anagyrine in lupine plants or coniine in poison hemlock
what wrong
Arthrogyrposis
what can lead to degeneration of intervertebral discs
loss of water and proteoglycans, hypocelluarlity, and increased collagen content
degeneration of intervertebral disks and ensuing __ result in development of __ at margin of vertebral bodies or adjacent to disk
intervertebral instability, osteophytes
what wrong
Intervertebral disc herniation
What does erysipleothrix rhusiopathie septicemia cause and in who
pigs leads to synovial joint and intervertebral disk lesions
what does T. Pyogenes cause and in who
suppurative arthritis in cattle and pigs
what does haemophilus parasuis (glassers disease) cause and in who
polyarthritis in 8-16 week old piglets
what does Borrelia burgdoferi cause and in who
Lyme disease, arthritis in dogs, cattle and horses
what does mycoplasma hyorhinis cause and in who
fibrinous polyarthritis in weaned pigs
what does mycoplasma hyosynoviae cause and in who
fibrinous polyarthritis in pigs > 3 months
what does mycoplasma bovis cause and in who
fibrinous to pyogranulomatous arthritis in cattle
what does caprine arthritis and encephalitis virus cause
chronic arthritis in goats
what could have caused these joint changes in goat
caprine arthritis and encephalitis virus
From pig- what wrong and what could’ve caused. Also had diamond skin lesions
Marked synovial hyperplasia and lymphoplasmacytic infiltrates
Cause: E. Rhusiopathie
