Pathology of Bone - Part 2

Question 1

Lead poisoning: Lead interferes with _______ activity.
Subtle bone lesions –> Increase bone _____ (_______) in the _______ –> “_____ line”

Answer 1

osteoclastic, density, osteosclerosis, metaphysis, lead

Associate lead with neurological problems. Animals, especially cattle, can get into oil from tractors, old batteries (lead apparently is sweet) –> neurologic necrosis/encepalopathy.

Question 2

Answer 2

Metaphyseal osteosclerosis, lamb,
Lead poisoning. From Jubb, Kennedy &
Palmer’s pathology of Domestic Animals-
Grant Maxie ed., 2007

After the exposure to lead, there is a focal area of osteosclerosis. This line can be recognized by radiologists because they see this line of increased bone density which is characteristic of lead toxicity.

Question 3

Hypervitaminosis A: The most well known syndrome is observed in ____ that consume high quantities of ____ ____ (high vitamin __ content) for a ____ period of time –> deforming ______ ______.

Answer 3

cats, bovine livers, A, long, cervical spondylosis

Bone lesions produced as a result.
Spondylosis is degeneration of vertebral bodies. In this case, cats that are suffering from hypervitaminosis A or Vitamin A toxicity can develop cervical spongilosis. Can produce lameness, neurological signs, compression of nerves in the area –> lamness.
Seen primarily in Austraila and Urugauy, but can also be seen here, where animals are slaughtered away from major cities. Killed in field, feed liver to cats –> unfortunately, excessive amounts of vitamin A in fresh liver produces changes in bone.

Question 4

This disease is more common in Australia and Uruguay

Answer 4

Hypervitaminosis A

Question 5

Cats affected by Hypervitaminosis A develop ______ formation around the ___ of the _____ vertebrae, _____ and ____.

Answer 5

osteophyte, joints, cervical, shoulder, elbow

Question 6

Hypervitaminosis A is also known as?

Answer 6

ankylosing spondylosis or disseminating ankylosing osteoarthropathy).

Question 7

Label this image

Answer 7

Ankylosis = fixation of a joint. Called this because degenerative changes you will see in cervical vertebrae results in production of osteofites. Nodules of new bone that are formed on the periosteal surface of the vertebra. Extends to adjacent vertebrae and produces fixation of vertebrae. Involve foramina where spinal nerves exit –> neurological issues.

Question 8

Necrosis (Osteonecrosis or _____), means ______ ______ and is the result of ______ injury.

Answer 8

, Osteosis, bone necrosis, ischemic

Question 9

Osteonecrosis is often the result of _____ but may also occur in _____ and _____ bone disease. Necrotic bone appears ____.

Answer 9

trauma, inflammatory, neoplastic, paler

Question 10

In cases of osteonecrosis or osteosis, microscopically you will see cell ____ with loss of ______ from their ____.

Answer 10

death, osteocytes, lacunae

Question 11

What is the outcome of osteonecrosis?

Answer 11

1. Depends on the quality of the collateral circulation. Influenced by the size and extent of necrosis and by the extend and strength of collateral circulation and local repair mechanisms.
2. Complete resorption and replacement of necrotic bone may occur if collateral circulation is well preserved/salvageable.
3. If collateral circulation is not well preserved/salvageable –> Formation of a “sequestrum” –> A piece of necrotic bone isolated from the remaining viable bone. E.g. in horses –> surgeons must remove the necrotic bone to stimulate proliferation of adjacent bone aka healing.

Question 12

Attempts to wall off a sequestrum will result in the formation of a layer of ______ tissue and _____ bone known as an “______”.

Answer 12

granulation, reactive, involucrum

Question 13

Answer 13

Foal, focal osteomyelitis (inflammation of bone - used b/c inflammation of bone marrow in addition to the bone itself) with sequestrum.
Distal end of a long bone.
Granular type of appearance; bottom is pale in comparison to top. Body makes an attempt to surround area of necrosis to initiate repair –> proliferation of granular tissue (light brown region above pale part). This tissue is called the involucrum.

Question 14

A traumatic bone fracture occurs when a _______/_______ bone is broken by ______ _____.

Answer 14

normal/healthy, excessive force

Question 15

A pathologic bone fracture is when an _______ bone is broken by _____ trauma or ____ weight bearing.

Answer 15

abnormal, minimal, normal
Can also be seen in animals with bone tumors. Neoplasm in bone –> weakens bone –> minor trauma –> pathological fracture.

Question 16

Complete or Incomplete is a type of?

Answer 16

bone fracture
Complete separation = complete transection of a bone

Question 17

Closed (simple) or Open (compound) is a type of?

Answer 17

Bone fracture
Closed = fracture of the bone but soft tissue around it, including the skin, is intact.
Open = severe trauma –> pieces of bone rupture through the skin.
- prognosis is more complicated because susceptible to secondary bacterial infection b/c bone marrow is exposed, severe damage of soft tissue.

Question 18

Comminuted is a type of

Answer 18

bone fracture
Bone breaks into several small fragments. E.g. race horse -> does not end well.

Question 19

Avulsed bone fractures are caused by the pull of a _____/muscle _______ at its _____ into bone

Answer 19

ligament, tendon, insertion
Tendons of muscle attached to periosteal surface. In seevere traum, pulling of area –> bone comes out with part of the tendon.

Question 20

Microfracture/ infraction bone fractures occure due to fracturing of _____ without ______ deformation of _______ bone.

Answer 20

trabeculae, external, cortical
Osteodystrophies can result in microfracture (compressive fractures of vertbrae with osteoperosis; weight bearing –> fracture of trabeculae of cancellous bone which is an example of microfracture).

Question 21

Morphological diagnosis?

Answer 21

Pig – vertebral abscess resulted in fracture of the vertebral body
and focal compression of the spinal cord, common sequel of tail
biting.
Pig was doing well, fed them, very excited/fighting for food. All of a sudden, find one of the pigs laying down on floor unable to stand with posterior paralysis. This is the typical presentation. When do autopsy, find presence of vertebral abscess. Suppurative inflammation –> Suppurative osteomyelitis/ Vertebral osteomyelitis. Loss of bone here.

Morpholoical Diagnosis = vertebral abscess OR focal suppurative vertebral osetomyelitis.

In pigs, this is a common sequel of tail biting. Infection in tail travels through blood vessels into vetrebrae –> abscess production

Question 22

Answer 22

Cornell, Dr. King’s show & Tell. Pathologic fracture,
Osteosarcoma, dog

Relatively common in dogs (malignant).
One of the presentations is that the animals may become acutely lame b/c you may have a pathological fracture.
Bone becomes weak due to proliferative tumor.

Question 23

Answer 23

Fracture repair
Bone usually has a very good healing capability, especially in younger individuals. With age, when get a fracture, it is more complicated (from 70s onward).
Read this part in your reference book

Whenever you have a complete fracture of a long bone, immediately after fracture you see the formation of a hematoma aka large blood clot. Hematoma builds a meshwork to facilitate the arrival of fibroblasts and new blood vessels. Also have MQ, some inflammatory cells trying to reabsorb necrotic debris, etc. that will result in osteoprogenitor cells that you see in the endiosteum and periosteum. Later on, more than a week later, you will see osteoprog → osteo blasts → build woven bone → repair starts. These osteoprog can also build cartilage. With time, this cartilage is completely replaced by bone and may have complete healing of fracture. Also important to maintain stability of fracture so that the healing process happens well. More mobility = less proper vascularization in the area. Instead of having lots of osteprog -→ more fibroblasts to produce more CT because more resistant to hypoxia.

Question 24

Answer 24

Healed fracture
In addition to an adequate blood supply, stability of bone fragments is of prime importance in fracture repair

Focal area completely replaced by bone.

May see even after years that there is a nodular change in ribs because healing was not achieve properly.

Question 25

What are complications associated with bone fractures?

Answer 25

* Bone necrosis (severe fracture → severe damage to blood vessels → focal areas of hemorrhage and areas of severe hypoxia → not achieve complete vascular degeneration in those areas → formation of a sequestrum (depending on location, surgically have to remove necrotic area to stimulate healthy bone proliferation and repair. * Nonunion fracture → pseudoarthrosis (false joint) formation. Seen sometimes in wildlife. * Osteomyelitis (compound fractures) → pieces of bone come out of skin and it took awhile for animal to go to et → develop osteomyeltiis. Even with antibiotic treatment → severe issues * Cachexia; especally in wildlife, if tehy have fractures/lesions, unable to feed themselves.

Question 26

Answer 26

non union fracture that healed primarily with CT. With time, there is the formation of a cavity in this area that can be lined with synovial membranes. Can move these areas around.

Question 27

Inflammation of the bone is also called?

Answer 27

Osteitis/ Osteomyelitis Inflammation of the bone is also associated with inflammation of the bone marrow, hence why we should use ostemyelitis.

Question 28

Aseptic inflammation --\> trauma may cause ______ with formation of exostosis (\_\_\_\_\_\_\_).

Answer 28

osteoperiostitis, osteophytes (nodules containing bone that are located usually on periosteal surface of the bone). The more common cause of osteitis is bacterial infection.

Question 29

Infection: Local or systemic (hematogenous route)

Question 30

Osteomyelitis is most common in _____ farm animals as the result of ______ or \_\_\_\_\_\_\_. Can also happen in?

Answer 30

young, bacteremia, septicemia. Can also happen in dogs and cats, but it is not as common.

Question 31

Omphalophlebitis is a common source of _______ in \_\_\_\_\_\_.

Answer 31

osteomyelitis, neonates Neonatal septicemia. Umbilical infections due to urine and feces presence in the barn → bacteremia → travel through blood to bone → osteomyelitis

Question 32

In piglets, an osteomyelitis infection often localizes in ?

Answer 32

vertebral bodies For some reason in piglets, vertebral osteomyelitis is very common.

Question 33

Osteomyelitis infection also tends to localize in ________ of ____ bones due to the microanatomy of \_\_\_\_\_.

Answer 33

metaphysis, long, vessels

Question 34

Answer 34

Noenatal infection → sepsis Bacteria circulating in the blood, can localize in the bone, and produce osteomyelitis. When we get neonatal cases in farm animals, during post mortem exam split seveal long bones to detect presence of osteomyelitis. most lesions of osteomyleiic in young animals is in the metaphysis immmediately underneath the growth plate. Why? B/c blood vessels coming from diaphysis come all the way close to the physis, turn around in a hsarp angle. B/c of angle, slowing down of blood in thia area, blood vessels are very thin, facilitate change of nutrients with growth plates, etc. so a bit leaky; Bacteria circulating in the blood has ability to come out into areasw → proliferate → osteomyeltisi → prliferate → suppurative (neutrophilic inflammation) exudate. Looks pale grossly, formation of cavities containing puss. Starts in metahysis, can spread to adjacent tissues, drain into the skin (fistulus tracks) b/c all of the proteolytic enzyes produced by neutrophils produced destruction of tissue. Inflammatory process from the bone extends into joints → supurative arhtriit.s. Foals with osteomyleitis can produce polyarthririst (swollen, large, carpal joints).

Question 35

Answer 35

Physitis has extended to the periosteum and metacarpal phalangeal joint, foal Primarily in young individuals (see growth plate hence why we know young). See focal area of pallor surrounded by red ring representing acute inflammation. Growth plate in this case is primarily gone.

Question 36

Answer 36

Embolic osteomyelitis, foal. Note Area of bone necrosis (arrow) See growth plate. Look in metaphysis immediately undeer growth plate, look for pale discoloration. See a small white dot = necrosis that is demarcated by reddish rim of inflammatory cells. Salmonella, e.coli can produce these types of lesions. Must culture to come up with diagnosis. Salmonella is important, especialy in foals.

Question 37

Answer 37

Bovine Actinomycosis, “lumpy jaw”, suppurative inflammation of mandible in cattle. Lesions in oral cavity → bacteria penetreate into mandible → Present with large mandible that is nodular. Presence of fistulus tracks draining onto surface of skin → alopecia.

Question 38

Answer 38

Bovine Actinomycosis, (“lumpy jaw”), - involvement of left maxilla UCVM Suppurative exudate is very characteristic of this.

Question 39

Answer 39

Chronic pyogranulomatous osteomyelitis – Actinomycosis, UCVM, OI Markedly large Presence of supurative exudate Defacement of normal architecture of nasal cavity. Bacteria produce chronic supurative and pyogranulomatous inflammation. Priliferation of neutrophils, MQ, multi nucleated giant cells, fibrosis, severe bone damage → all seen in actinomyosis

Question 40

Answer 40

Actinomyosis Gram positive, filamentous bacteria Port of entry = usually this organism enters through local lesions in the oral cavity that allows the bacteria to penetrate in between the teeth ang gum -→ osteomyolitis. This is a chronic conditionn resulting in pyogranulomatous inflammation. Neutrophils with viable numbers of MQ, multinucleated giant cells → destroys the bones. Lesions located in jaw and maxilla.

Question 41

What can be seen here?

Answer 41

Pyogranulomatous Osteomyelitis, Actinomycosis → Affects hard tissue like the bone. neutrophils, MQ

Question 42

What can be seen here?

Answer 42

Splendore Hoeppli Dark pruple = bacteria colony Splenodre hoeppli = position of Ab/Ig complex. Characteristic of Actino Sulfur granules is an important feature of this disease.

Question 43

What can be seen here?

Answer 43

Gram stain of lesions: Gram positive bacteria, Actinomyces bovis, UCVM, OI Filamentous

Question 44

What can be seen here

Answer 44

“Lumpy Jaw” (Actinomycosis) – cow. Actinomyces bovis. Note osteolysis of the macerated and bleached bone specimen Macerate this bone, this is how it will look. Produces severe damage of bone. Bone lysis in lesions and bone proliferation occurring simultaneously. Suppurative exudate can be seen on the surface.

Question 45

Hypertrophic pulmonary __________ or osteopathy was sporadically reported in ______ (“Marie’s Disease”) and _____ animals, especially \_\_\_.

Answer 45

osteoarthropathy, humans, domestic, dogs Can also be seen in mares.

Question 46

Hypertrophic pulmonary osteoarthropathy is usually observed in individuals with an \_\_\_\_\_-\_\_\_\_\_\_ ____ occupying ____ (\_\_\_\_\_, \_\_\_\_).

Answer 46

intra-thoracic space, mass, tumor, abscess

Question 47

Hypertrophic pulmonary osteoarthropathy is characterized by painful _____ of limbs caused by ______ bone ______ (\_\_\_\_\_\_,\_\_\_\_\_) in ___ bones.

Answer 47

swelling, periosteal, proliferation, periostitis, hyperostosis, long Lameness, swollen forelimbs (can also be all limbs)

Question 48

Bone changes due to Hypertrophic pulmonary osteoarthropathy can _____ if the space-occupying lesion in the _____ \_\_\_\_ is removed.

Answer 48

regress, thoracic cavity

Question 49

Answer 49

The disease is also occasionally observed. In young dogs with rhabdomyosarcomas of the urinary bladder and mares with ovarian tumors. Radius, ulna, metacarpals; newly produced bone on the surface of the periosteum. This is a characteristic lesion of this disease. Bladder? Text caroline

Question 50

Canine craniomandibular osteopathy (“\_\_\_\_ \_\_\_\_”)

Answer 50

Lion Jaw

Question 51

Canine craniomandibular osteopathy is a ______ disorder confined to the bones of the \_\_\_\_, especially the \_\_\_\_\_, \_\_\_\_\_ and _____ bones

Answer 51

proliferative, skull, mandibles, occipital, temporal Mandible appears to be “powerful”

Question 52

Canine craniomandibular osteopathy is most common in what dog breed? Explain why

Answer 52

West Highland White Terriers where a genetic etiology is suspected (also reported in several other breeds)

Question 53

Canine craniomandibular osteopathy is usually recognized at \_\_-\_\_ ____ of age • Possible infectious agent _____ but not \_\_\_ • Affected dogs may exhibit proven when ____ or ____ to open their ____ to eat.

Answer 53

4-7 months, suspected, chewing, inability, mouth Genetically inherited May have pain when eating.

Question 54

What condition may this dog breed have?

Answer 54

West Highland White Terrier Lion Jaw Animals usually have to be euthanized if lesions are so severe taht tehy can not eat.

Question 55

Answer 55

Canine craniomandibular osteopathy (“Lion Jaw”) Osteofites of new bone seen on periosteal surface. Occipital bone, tympanic bulla can also be affected

Question 56

Primary tumors are more common than ____ tumors

Answer 56

secondary In humans, it is the opposite. Breast tumors in woman can metastatize to bone.

Question 57

Bone neoplasia is primarily observed in ____ and to a lesser extend \_\_\_

Answer 57

dogs, cats

Question 58

In cases of bone neoplasia, Tumors of __ and ____ cell-lines are the most common

Answer 58

bone, cartilage

Question 59

In dogs most primary tumors of bone are?

Answer 59

malignant

Question 60

In \_\_\_\_, ____ and other ____ animals benign tumors of bone are more common than malignant ones.

Answer 60

horses, cattle, domestic

Question 61

List some Primary Bone Neoplasms

Answer 61

* Osteoma = arise from osteoblasts benign * Ossifying fibroma * Osteosarcoma * Chondroma = arise from cartilage benign * Chondrosarcoma * Multilobular tumor of bone = specific type of tumor on tpp of head of dogs; combo of cartilage + bone + CT Primary = arise from cells in articular tissue

Question 62

What can be seen here?

Answer 62

Osteoma, maxilla, Sheep-McGavin Enlargement of maxilla; is not infiltrating outside area; osteoma Can see a bot = chronic rhinitis in sheep; live in sinuses. CAn live in molar area and produce meningitis?

Question 63

\_\_\_\_\_\_\_\_\_ is the most common primary bone tumor in dogs and cats

Answer 63

Osteosarcoma

Question 64

The highest incidence of osteosarcoma occurs in _____ breeds like ?

Answer 64

Large, St. Bernard, Great Dane, Irish Setter, Boxer, Doberman, Rottweiler and Labrador Retrievers

Question 65

Mean age of dogs affected by osteosarcoma is ?

Answer 65

7.5 years but dogs less than 2 years old can be affected tumors can be associated with trauma

Question 66

Osteosarcoma is most common in

Answer 66

Most common in male dogs Not as accurate because studies are not as big as human studies

Question 67

Answer 67

In the dog osteosarcoma has a relatively specific site predilection: **“Close to the knee and away from the elbow”** Predilection sites: practically from every bone in the body, but when you divde axial = cervical columbn or appendicular appendicular is more common Humerus = 15% distal radius and ulna = 28%

Question 68

What can be seen here?

Answer 68

Osteosarcoma, 11 y-old Female Rottweiller Distal radius, ulna Eventually dog became very lame → clinical signs → euthanized

Question 69

Answer 69

Osteosarcoma, 11 y-old Female Rottweiller Presence of proliferative lesion in radius and ulna Producing osteod Areas of loss of densitty can be seen sometimes too. Animals rarely survive more than 1 year. Prognosis is not good. Usually remove the leg. Need to make sure tumor has not metastaized. Eventually die of metatastic disease.

Question 70

What can be seen here

Answer 70

Osteosarcoma, 2 year-old Poodle, Atlantic Veterinary College, Lesion in distal femur Proliferative lesion around bone infiltrates into medullary cavity. Difficult to see very much because malignant tumors do not have clear boundaries. nodular proliferation is hard. Osteoblasts producing osteod can also is soft so can also find this here. ? Need to do histology to determine is osteosarcoma or fibrosarcoma.

Question 71

Chondrosarcoma = malignant tumor of \_\_\_\_\_\_\_\_\_\_ Accounts for approximately \_\_\_\_% of primary bone tumors in the dog • ______ in other domestic animals • In all species it involves _____ bones (?) more often than long bones. Less in _____ bones.

Answer 71

chondrosites, 10, Rare, flat, ribs, nasal turbinates and pelvis, long

Question 72

Waht can be seen here

Answer 72

Chondrosarcoma, skull, dog Lesion is not benign; compressing underlying brain. Severe neurological signs. tumor appears to be also ifiltrating the frontal sinus; not confined to particular area. In this area see shiny tissue representing cartilage; arising in flat bone so very likely we are dealing with chondrosarcoma (can have areas of bone prolfieration) osteosarcoma can have areas of cartilage. Based on knowing that you can diagnose which tumor type it is

Question 73

Answer 73

Chondrosarcoma, rib, cat, Zachary (ed.), Pathologic Basis of Veterinary Disease, 2017