Boney bones

ktepps's version from 2016-11-21 20:50

Section 1

Question Answer
bone inflammation often orginates wherethe vascular regions aka the medullary cavity(osteomylitis) or the periosteum (periostitis)
general term for inflamation of the boneosteitis
osteomyelitis is typically a result ofan infection, or tramatic injusry to the periosteum (periostitis)
three routes of bone inflammation 1)direct via implantation/inoculation(penetrating wound/open fracture/surgical implants) 2)direct infection from an infected site 3)hematogenous
polyostatotic osteomyelitis akamultifocal osteomyelitis (mostly young animals)
traumatic wound infection into bonefocal osteomyelitis (adults mostly)
CS of osteomyelitis lameness, recumbency, draining tracts, fever and or paresis
periodontitisDirect implantation or extension of an existing infection
what is the most important cause of osteomyelitis in domestic animalsbacterial infections
if a neonate is septic you should thinkfailure of passive transfer resulting in bacterial infection or polyostotic dz
what part iof the long bone is important to hematogenous ostemyelitismetaphyseal region-as it contains the fenstrated capillaries that physeal metaphseal interface. they make a sharp bend here then open into the larger sinusoidal vessel
what is another area of importance in long bones for infwection seedingthe subchondral epiphyseal bone, this is a site of ossification as well
basically where the blood goes to grow the bonesthe bacteria will go to grow too!
Metaphyseal/epiphyseal osteomyelitis initially is characterized by edema, fibrin deposition and the influx of neutrophils
osteomyelitis is often bordered byproliferative bone and granulation tissue
septic arthritis can result fromextension of osteomyelitis into the adjacent joint space
infacted bone differs from healthy bone howit is distinctaly pale while vasculerized bone has a nice red area of hematopioetic tissue
what are three common entry points for neonatal infectionsthe umbilicus, respiratory tract or gastrointestinal tract

Section 2

Question Answer
what is a sequestruma variably-sized fragment of infected, devitalized and necrotic bone isolated from its blood supply and surrounded by a collar of inflammatory exudate/granulation tissue (involucrum)
cloacaA draining tract usually from the involucrum to the skin or adjacent joint space
how is a sequestrum treatedsugically needs removed. antiobiotics will not reach it!!
horses get what in the cannon bonessequstriums!
how are vertebrae formedendochondral ossification and have two epiphyses and growth plates within the vertebral body(that means infections like that spot)
what three pathogens love it up in the spine bones Brucella spp, Staphylococcus aureus, Trueperella pyogenes
diskospondylitisInflammation that localizes to the vertebral end plate and intervertebral disk
mycotic infection usually seen in german shepherdsaspergillus terreus diskospondylititis
IVDintervertebral diskospondylitis
describe the lesions with IVDEarly lesions are suppurative, gradually becoming more plasmacytic. With chronicity, the IVD is destroyed and replaced with fibrous tissue and proliferative bone
lumpy jawcattle=mandibular Actinomyces bovis aka actinomycosis
how is lumpy jaw characterized by both bone loss and proliferation >=0 the mandible is greatly enlarged and comprised of fibrous tissue, remodeled trabecular bone, inflammation, necrotic tissue/debris and interspersed bacterial sulfur granules
atrophic rhinitispasturella multocida-Local absorption of the toxins leads to osteonecrosis of the turbinate bones
Mycotic osteomyelitisinhalation of the systemic fungi- Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum or Blastomyces dermatitidis
inflammatory response to mycotic osto is whattypically pyogranulomatous and lesions are most often seen in horses and dogs
fungemiasystemic infections via relatively low-grade fungal pathogens Aspergillus terreus or Paecilomyces
viral infections inhibit the GRL meaning whatGRL (growth retardation lattice) is a region of persistent primary spongiosa parallel to the physis. In the GRL, the primary spongiosa has increased cross connections between the bony trabeculae (area of inhibited osteoclast function)

section 3

Question Answer
synovitis or arthritis isJoint inflammation
Synovitis indicatesinflammation of the synovium (the lining of the joint capsule)
arthritis meansinflammation of the joint capsule and intra-articular structures
tenosynovitis indicatesinflammation of the tendon sheath; this lesion is a common sequela of arthritis
osteoarthritisArthritis can result from (or cause) osteomyelitis
know the stages of and mixing stages over arthritisserious->fibrinous->supperative so you would get “serofibrinous” and “fibrinosuppurative”
synovial hyperplasiathe synovial villi become markedly hyperplastic, hyperemic and expanded with edema and inflammatory cells
pannusa fibrous-granulation tissue membrane originating at the synovial membrane and cover the articular cartilage
Pannus formation can causeimpaired chrondrocyte function and nutrition, leading to cartilage necrosis and eventually facilitate joint ankylosis
septic arthritisbacterial infections of joints will have toxic neutrophils ITS A MEDICAL EMERGENCY
suppurative osteomyelitisResult an extension of the infection into the subchondral bone=> will lead to degenererative joint Dz that started as destruction of the articular cartilage via bacterial proteases and lysosomal enzymes
Non-infectious arthritis akaimmune-mediated arthritis
erosive arthritis(one type of immune mediated)the inflammatory process is quite severe and is focused directly on the synovial joint
CS of erosive arthritisby pain, severe inflammation, cartilage destruction and pannus formation with eventual cartilage and subchondral bone destruction/proliferation. results in loss of joint function luxation or ankylosis
examples of erosiveRheumatoid-like arthritis of dogs, polyarthritis of Greyhounds and feline progressive polyarthritis
non erosive arthritisthe inflammatory process is not focused on the joint, but is located elsewhere in the body. the inflammitory mediators just end up in the joint causing inflammation. THUS NO DESTRUCTION JUST PAIIIIIIINNNNNNN!
infectious and non infectious joint dz are both characterized bysupprative inflammation within the synovial fluid

section 4

Question Answer
Metabolic bone disease (MBD) aka ?osteodystrophy= a family of bone disorders resulting from a disturbance of calcium homeostasis
MBD can be the result of ?multiple pathogenic mechanisms including endocrine, toxin exposure, genetic and nutritional
basically MBD is whatthe result of a failure of bone production, mineralization and/or maintenance
Nutritional deficienciesthe balance of nutrients is often more important than absolute quantities
Clinically MBD results in ?soft bones, pathologic fractures (ofen folding), pain, disuse and deformities
Key pointdifferent osteodystrophies often co- exist
OsteoporosisReduced bone mass- porous, thin and brittle bones
cause of osteoporosisprotein calorie malnutrition mobilization, dietary calcium deficiency, glucocorticoid excess, menopause in human beings
Osteomalacia(adult animals) decreased bone mineralization(accumulation of osteoid/soft bones)
cause osteomalaciaVitamin D deficiency, phosphorous deficiency
Ricketsdecreased bone mineralization
cause of ricketsVitamin D deficiency, phosphorous deficiency
Fibrous osteodystrophyDecreased bone mass because of resorption and replacement by fibrous tissue, rubbery bone
how many times higher is the concentration of extra cell to intra cell calcium10,000 timesz higher
totaly plasma calcium is usually10 mg/dl

section 5

Question Answer
Osteoporosis is characterized bya pathologic reduction in bone mass (or density) resulting in clinical disease (pain, fractures, bone deformities)
osteopeniaa reduction in bone mass without clinical disease
growth arrest lineslines are "archived into the metaphysis" as a layer of horizontally fused spicules of primary spongiosa. Growth arrest lines are visible radiographically and grossly when the bone is split sagittally
know his causes in packet 2 page 5you highlighted it yo
histological features of osteoporosisquality of the bone is normal, however, there is less of it! In the metaphysis, the primary spongiosa is typically normal while the secondary spongiosa is sparse to absent
where do fractures of osto bones happenCompression (aka collapse) fractures, partial fractures through the trabecular bone (aka "infractions") or bone deformities may or may not be present. In the cortical bone, porosities may or may not be evident
Fibrous osteodystrophy (FOD) always results from increased PTH secretion
**causes of FOD1. Primary hyperparathyroidism 2.Secondary hyperparathyroidism (renal) 3. Secondary hyperparathyroidism (nutritional) 4. Pseudohyperparathyroidism (humoral hypercalcemia of malignancy, HHM)
CS of functional parathyroid adenomas (primary parapthyroidism)in high PTH levels, hypercalcemia, PU/PD, vomiting, weakness and metastatic mineralization
secondary hyperparathyroidism bcrenal fuckery (you should know how this works if not go read the fucking notes)
nutritional secondary hyperparathyroidismchronic dietary imbalance of P and Ca (you know the rest if not go read)
Pseudohyperparathyroidism aka(humoral hypercalcemia of malignancy->know how it works
two histologically important features of fibrous osteodystrophy1. increased osteoclast-mediated bone resorption (the “osteodystrophy” part) 2.increased compensatory intratrabecular fibrous tissue deposition (the “fibrous” part)
the net effect of fibrous osteodystrophy is ?BONE RESORPTION AND REPLACEMENT WITH FIBROUS TISSUE
Histological features of osteomalaciaincreased peripheral band of unmineralized osteoidal matrix (aka “wide osteoid seams”) along with active osteoclastic resorption which is generally confined to cortical bone
the growth plates in osteomalacianormal or absent (grown ups)
Lesions of rickets are most prominent wherewhere cartilage contributes significantly to skeletal growth (eg sites of endochondral ossification/physis)
Histological features of ricketsThickened/dysplastic physis. Trabecular bone demonstrates wide osteoid seams. Retained cartilage cores are often present in the secondary spongiosa. The cortices of the long bones are often thin and may have folding fractures of the cortex
what happens in the metaphyseal regoin of long bones in rickets animalsintertrabecular fibrous tissue deposition as a structural compensatory response to the poorly mineralized bone
what is the Osteoclast numbers likemay be reduced and microfractures (infractions) can be present in the metaphysis
what bones are really fucky from MBDjaw bones and vertebra!

section 6


Question Answer
bone tumors. who do you think ofdogs
what percent of bone tumors are osteosarcomas (OSA)80
what percent of bone tumors are chondrosarcomas (CSA)10
what percent of bone tumors are are hemangiosarcomas (HSA) or fibrosarcomas (FSA)7
where can primary bone tumors arise fromany of the cellular components present in bone: osteoblasts, chondroblasts, fibroblasts, adipocytes, endothelium of blood vessels and cells of the hematopoietic system
what are the most common tissues that bone tumors arise fromosteoblasts and chondroblasts (bone and cartilage-forming tissues)
Multilobular tumor of boneMalignant
Tumors of bone marrowlymphoma, multiple myloma and histocysticsarcoma
Benign/dysplastic proliferative bone lesionsChondroma, Osteoma, Ossifying fibroma, Fibrous dysplasia, Osteochondroma
Tumors of synovial jointsHistiocytic sarcoma, Synovial myxoma , and Synovial sarcoma