Path- Bones and Joints 1

kelseyfmeyer's version from 2015-09-08 17:10

GENERAL Bones/ joints

Question Answer
(review) what's the AE complex?
what are the 8 possible responses of bones to injury?Atrophy, Hypertrophy, Hyperplasia, Metaplasia, Neoplasia, Degeneration, Necrosis, Inflammation
Disruption of endochondral ossification(cartilage turning to bone) affects what?affects metaphyseal (growth plate) trabeculae (spongey bone, the little boney struts that compose this)
bone can adapt to damage and abnormal use by...changing its shape
with systemic dz and altered use, bone can change its...mass
how is the structure of bone different if it is deposited slowly as opposed to slowly?if deposited rapidly, it is woven( haphazard organization of collagen fibers and is mechanically weak). If it's deposited slowly, it is lamellar ( regular parallel alignment of collagen into sheets ("lamellae") and is mechanically strong)
If the periosteum is injured, how does it often respond? (periosteum is membrane that covers the outer surface of all bones) it will often form bone in response to injury
(review) Osteogenic cell is what and where does it live?osteoblast, secretes osteoid/matrix. Once is it surrounded by the matrix is creates, it is in the lacunae and turns into an osteocyte with it's little processes
immature bone is what structure, and mature bone is what structure?immature is woven. mature is lamellar
(review) what is the functional unit of cancellous/spongey bone? compact/cortical bone?spongey= trabeculae. compact= osteons (Haversion Systems) (swirly thing with haveersion canal in middle and lacunae all around in swirls)
flat bones do what kinda ossification?Intramembranous ossification
Cartilagenous models/long bones do what kinda ossification?Endochondral ossification
Joints--> articular cartilage--> what are the 4 responses this cartilage can have to injury?(1) Chondromalacia (2) fibrillation (3) erosion (4) eburnation
Chondromalacia is what?softening/degenerating of cartilage
what is fibrillation of articular cartilage?early degenerative change of articular cartilage, there is superficial erosion of cartilage (usually due to loss of proteoglycans, unmaskinig of collagen fibers, increased water content in chondrocytes)
what is eburnation of articular cartilage?complete loss of articular cartilage (+ osteoclerosis of subchondral bone)
Joints--> Articular capsule/synovium/synovial fluid--> what is the response of these structures of injury?Villous hypertrophy and hyperplasia (“velvety” appearance due to formation of synovial villi covered with hyperplastic synoviocytes)
Joints--> Subchondral bone--> what is the response of this to injury?Sclerosis (hardening of tissue)

Abnormalities of growth and development

Question Answer
Osteopetrosis is a disorder of bone _________resorption
Congenital cortical hyperostosis is a disorder of bone ___modeling
Craniomandibular osteopathy is a disorder of bone _________modeling
Chondrodysplasias (chondrodystrophies) are disorders of...endochondral ossification
Osteochondrosis dissecans (OCD) is a disorder of..endochondral ossification
Epiphysiolysis is a disorder of..endochondral ossification
Cervical vertebral myelopathy is a disorder of...endochondral ossification ((includes (Cervical vertebral static stenosis (CVS) and Cervical vertebral instability (CVI) )
Osteopetrosis is aka what kinda dysplasia? another aka?metaphyseal dysplasia, aka marble bone dz
Who is osteopetrosis inherited in?autosomal recessive in Angus cattle (in birds it can be induced by leukosis virus)
what is happening in osteopetrosis?failure of osteoCLASTS to resorb (remodel) the primary spongiosa, or the secondary spongiosa (p.s. is the first bone that is formed, which is resorbed, and then the secondary bone structures are formed)
osteopetrosis is a failure of what cells?osteoclasts
osteopetrosis leads to osteo__SCLEROSIS
what's weird about the spongiosa (cancellous bone) in osteopetrosis?it extends into the medullary cavity! (hence you will see spicules in the cavity)
what problem can occur because of osteopetrosis, and why?APLASTIC ANEMIA, because there is a bunch of bone in the medullary cavity instead of marrow
gross lesions of osteopetrosis?bones are dense and thick (diffusely solid), and small or no medullary cavity marrow spaces (it is filled with spicules of bone with central cores of calcified cartilage)
how do osteopetrosis affected angus calves appear?stillborn, brachygnathia inferior (shortened mandible), impacted molar teeth, deformed cranial vaults >> compress the brain.... and patholgical fractures
are bones affected with osteopetrosis easier or harder to break?EASIER TO FRACTURE bc lack tensile strength (think green vs dry stick)
Congenital cortical hyperostosis aka? WHO gets this, and how?aka diaphyseal dysplasia. This is a autosomal recessive inherited disorder in pigs
what is happening in congenital cortical hyperostosis?there is disorganization of the perichondrial ossification groove, leading to a chondrogenic membrane around the growth plate.....which means there is new periosteal bone formation on major long bones of the limbs and edema (in short, basically abnormal periosteal bone formation on long bones which increases the diameter of the bones)
how is the growth plate affected in congenital cortical hyperostosis?it inc in diameter
what are the gross lesions of congenital cortical hyperostosis?piglets will have very thick, swollen, hard, rigid bones, and are often stillbirths or early neonatal death because of other defects ((like starvation and cardiac insufficiency)
what problem can occur because of congenital cortical hyperostosis?edema, because swollen out bone is blocking lymph flow
Craniomandibular osteopathy (CMO) is aka, happens in WHO, and WHY?aka "westie jaw"; "scottie jaw"; "lion jaw". Happens in West Highland white or Scottish terrier dogs. It can be either idiopathic or autosomal recessive
what is happening in Craniomandibular osteopathy (CMO)?new periosteal bone formation and irregular resorption leads to irregular thickening of bones
how does Craniomandibular osteopathy (CMO) appear grossly?bilaterally symmetrical thickening of the mandibular, occipital and temporal bones, tympanic bullae (often severely affected) and less often the limbs. There will be atrophy of associated musculature (painful condition)
what are Chondrodystrophies?1°primary lesions in growth cartilage
what are the three types/locations of 1°primary lesions in growth cartilage?physis, articular epiphyseal [AE] complex and epiphyseal cartilage
Chondrodystrophies are ___ dwarfismdisproportionate dwarfism--> short-legged with normal-sized heads
how do animals get Chondrodystrophies?(1) idiopathic (2) inherited errors in genes that control chondrogenesis
what is the one type of chondrodystrophy in cattle he told us to focus on?Dexter (breed) "bulldog" calves
(not sure if important) what is Osteochondrosis?heterogenous group of lesions in growth cartilage of young animals--> focal or multifocal failure (or delay) of endochondral ossification
(not sure if important) hallmark of the gross lesions of osteocondrosis?focal or multifocal retention of growth cartilage due to its failure to become mineralized and replaced by bone (failure of endochondral ossification)
(not sure if important) etiology of osteocondrosis?can be idiopathic, or high incidence in species bred and fed to achieve maximal body weight at a young age, or Cu deficiency induced by excess dietary Zn
(not sure if important) there is a greater incidence of osteochondrosis in dogs who...growing dogs fed high calcium diets
(not sure if important) what are the lesions of osteochondrosis?well demarcated wedge of white, firm hyaline cartilage at the AE (articular epiphyseal) complex or physis, stages of resolution or 2°necrosis, hemorrhage and mineralized debris in the adjacent bone
(not sure how important) common sites of osteochondrosis in various animals?distal femurs of pigs, distal femur, distal tibia, and vertebral articular facets of horses, proximal humerus of dogs, proximal tibia of rapidly growing birds
what is Osteochondritis dissecans (OCD)?when there are dysplasias at the AE complex (articular-epiphyseal)
Osteochondritis dissecans (OCD) causes what to happen?dysplasia of articular-epiphyseal complex---> formation of clefts in the retained cartilage + fracture of the overlying articular cartilage--> cartilaginous or osteochondral flap
if the flap caused by OCD is fractured off, what is it called and what does it do?called a "joint mouse" which is now free in the joint space... this can interfere with mechanical movement of the joint
Sequelae of osteochondrosis dissecans?degenerative joint disease, ulceration and exposure of subchondral bone, lameness
what is Epiphysiolysis?separation of epiphysis from the metaphysis because of fissure formation horizontally through the physis
what is epiphysiolysis NOT associated with?not associated with focal or multifocal dysplasia(as in osteochondroses) (it's bc of because of fissure formation horizontally through the physis)
lesions for epiphysiolysis?horizontal fissure/fracture through the physis + complete or partial separation of the epiphysis from the metaphysis
Cervical vertebral myelopathy (CVM) is caused by what?2°to static or dynamic compression on the spinal cord by abnormal cervical vertebrae which can cause this compression constantly due to absolute stenosis of the canal (static compression) or intermittently during movement [flexion] (dynamic compression)
Cervical vertebral myelopathy (CVM) is aka? what are the two types?aka "wobblers syndrome". (1) static type (2) instability/laxity type
what is static type Cervical vertebral myelopathy (CVM) associated with?malformation of vertebrae, osteochondrosis (disturbance of endochondral ossification)
what is the instability/laxity type of Cervical vertebral myelopathy (CVM) associated with?increased mobility of cervical vertebral joint (associated with rapid growth)
two specific examples of Cervical vertebral myelopathy (CVM) (and who is affected?)(1) Cervical vertebral stenotic myelopathy (horses) (2) Cervical spondylomyelopathies (dogs)
Cervical vertebral stenotic myelopathy happens in who? what are the problems/lesions associated with it?HORSES (horses are narrow-minded) and there will be incoordination, abnormal locomotion, compression of spinal cord, ataxia, narrowing of vertebral canal, myelomalacia
what are the two syndromes of Cervical vertebral stenotic myelopathy (horses)?(1) Cervical static stenosis (2) Cervical vertebral instability
Cervical vertebral myelopathy (CVM)--> Cervical static stenosis happens in who? what causes it? where is the affecetd area?OLDER horses, 1-4 years (older horses are more set (static) in their ways) Usually due to inherited, nutrition, environment, vertebral malformation, articular subluxation. narrowing @ C5-C7
Cervical vertebral myelopathy (CVM)--> Cervical static stenosis--> lesions?hypertrophy of ligamentum flavum, dorsal narrowing of vertebral canal @ C5-C7 (involves the less mobile verts), compressive myelomalacia, fibrillation(upper layers sloughing), eburnation(loss of articular cartilage), osteophytes (bone spurs)
Cervical vertebral myelopathy (CVM)--> Cervical vertebral instability--> happen in who? what causes this?happens in YOUNG horses (younger= more unstable in general), and is usually due to rapid growth, genetic. instability @ C3-C5
Cervical vertebral myelopathy (CVM)--> Cervical vertebral instability--> lesions?fibrillation(upper layers sloughing), eburnation(loss of articular cartilage), osteophytes (bone spurs). narrowed vertebral canal > compression of spinal cord
Cervical vertebral stenotic myelopathy (instability or stenosis) BOTH lead to WHAT?spinal cord compression, myelomalacia, ataxia