Musculoskeletal Exam 1

Front 1

what disease is associated with intramedullary sclerosis?

Back 1

panosteitis

Front 2

how does panosteitis present radiographically?

Back 2

intramedullary sclerosis, especially in the appendicular skeleton

Front 3

after a bone insult occurs, how long does it take for:
- periosteal reactions to occur?
- bone lysis to occur?

Back 3

- periosteal reactions: 10-14 days
- bone lysis 3-5 days

Front 4

what are three basic categories of periosteal reactions, as they appear radiographically?

Back 4

1. solid
2. lamellar (onion skin)
3. interrupted

Front 5

what are two radiographic presentations for solid periosteal reactions?

Back 5

1. smooth
2. irregular

Front 6

what are three radiographic presentations for interrupted periosteal reactions (in order of increasing aggressiveness)?

Back 6

1. spiculated
2. sunburst
3. amorphous

Front 7

what are two subjective assessments of the zone of transition in a bone reaction and what do they tell you about the pathologic process?

Back 7

1. length: the longer the zone of transition, the more aggressive the lesion
2. margins: well-defined margins are inactive; poorly-defined margins are active

Front 8

pathologic new bone formation at the origin or insertion (to a bone) of a tendon, ligament, or joint capsule

Back 8

enthesophyte

Front 9

what is an enthesophyte?

Back 9

pathologic new bone formation at the origin or insertion (to a bone) of a tendon, ligament, or joint capsule

Front 10

what are the three most common radiographic signs of DJD? What are five other less common findings?

Back 10

1. intracapsular soft tissue swelling
2. osteophytes at the perichondral margin of the joint ("bone spur"/lipping)
3. enthesophytes
- others -
1. joint mice
2. sub-chondral bone sclerosis
3. sub-chondral bone cyst
- even less common -
4. decreased joint space (when weight bearing)
5. sub-chondral bone erosions (more common in LA)

Front 11

what is the pathologic process of osteophyte formation?

Back 11

articular cartilage proliferation in non-weight bearing areas of joint → outgrows nutrient supply and dies → invaded with BV → replaced with bone

Front 12

what are the two most common locations of osteophyte formation in DJD of the shoulder?

Back 12

1. caudal to the infraglenoid tubercle
2. caudal to the humeral head

Front 13

what are the six physes of the shoulder and elbow joints?

Back 13

1. supraglenoid tubercle
2. head of the humerus
3. distal humerus
4. anconeal process of the ulna
5. olecranon process of the ulna
6. proximal radius (neck)

Front 14

where are the three most common sites of osteophyte formation in DJD of the elbow joint? What are two other less common places that appear in more severe disease?

Back 14

1. the anconeal process of the ulna
2. the head of the radius
3. the medial coronoid process of the ulna
4. the lateral aspect of the distal humeral condyle
5. the medial trochlea of the humerus

Front 15

what is a common radiographic prognostic sign of early canine hip dysplasia?

Back 15

the Morgan line, a curved enthesophyte on the distal neck of the femoral neck

Front 16

in a normal canine coxofemoral joint, how much of the acetabular rim should overlap the femoral head?

Back 16

at least 50%

Front 17

in DJD of the stifle, what are two signs of intracapsular soft tissue swelling? What are two common places of osteophyte formation?

Back 17

- ICST swelling: cranial displacement of the infrapatellar fat pad and obliteration of the caudal fascial stripe sign
- osteophytes on the patella and the medial trochlear ridge of the femur

Front 18

what usually causes enthesophytes?

Back 18

they occur secondarily to chronic strain, trauma, or previous avulsion at the site

Front 19

what happens to the femoral neck in hip dysplasia?

Back 19

it thickens

Front 20

what are four diseases that can cause intracapsular mineral bodies in the appendicular skeleton?

Back 20

1. avulsion fragment
2. OCD (joint mouse)
3. synovial osteochondroma
4. chondrocalcinosis

Front 21

rounded mineral bodies in the joint caused by metaplasia and mineralization of synovial membrane

Back 21

synovial osteochondroma

Front 22

what are nine general radiographic signs of DJD

Back 22

1. intracapsular soft tissue swelling
2. joint space alterations
3. periarticular new bone (osteophytes)
4. perichondral new bone (osteophytes)
5. subchondral osteosclerosis
6. soft tissue mineralization
7. subchondral osteolysis
8. subchondral bone cyst
9. joint mice

Front 23

what causes a decrease in the width of joint space in DJD?

Back 23

destruction of the articular cartilage

Front 24

what causes an increase in the width of joint space in DJD?

Back 24

acute and sever inflammation due to synovial effusion

Front 25

what causes periarticular new bone formation in DJD?

Back 25

excessive buildup of cartilage outgrows the ability of the synovial fluid to nourish it. It dies and mineralizes in non-weight bearing areas of the joint to attempt to stabilize the joint.

Front 26

in DJD, where does perichondral new bone form?

Back 26

at the chondro-synovial junction, fibrocartilage elements form and mineralize into osteophytes

Front 27

what is the etiopathogenesis of subchondral osteosclerosis in DJD?

Back 27

usually caused by bone-on-bone contact in weight-bearing joints due to the loss of articular cartilage, sclerosis is formed by hypertrophy of the trabecular bone to compensate for the increased weight-bearing requirement of the bone

Front 28

what are four important pieces of information to take in the history for an orthopedic exam?

Back 28

1. chief complaint
2. manner of onset (acute < 10d, chronic)
3. signs seen by the owner
4. duration of signs

Front 29

what percentage weight does a dog bear on its forelimbs?

Back 29

60%

Front 30

what are varus and valgus?

Back 30

- varus = "bow-legged"; a deformity of the limbs toward the midline
- valgus = deformity of the limbs away from midline (e.g. the front legs of a Basset hound)

Front 31

what are three important muscle masses to palpate when examining a dog for lameness?

Back 31

- mm of the spine of the scapula
- mm in relation to the greater trochanter
- quadriceps

Front 32

what are five characterizations that should be used to describe the specifics of a lameness in the dog?

Back 32

1. weight-bearing vs. non weight-bearing
2. neurologic or orthopedic
3. appendicular or axial
4. bone vs. soft tissue injury
5. specific joint vs. multiple joint involvement

Front 33

for a forelimb lameness in a dog, what is an important neurological rule-out

Back 33

peripheral nerve sheath tumor

Front 34

what is the normal sitting posture of a dog that is not lame?

Back 34

the tuber ischii rests on the tuber calcanei

Front 35

characterize a Grade 1 lameness and a grade 4 lameness in the dog (1-4 grading scale)

Back 35

- Grade 1: 75% weight-bearing
- Grade 4: non weight-bearing

Front 36

when a dog is lame in the front, when in motion, how does head position correlate to lameness?

Back 36

the head goes down on the sound limb; the head goes up when weight is baring on the lame leg to shift weight away from that limb

Front 37

what two techniques are used to assess a cranial cruciate tear in a dog?

Back 37

tibial compression and cranial drawer

Front 38

what test is used in a specific orthopedic of the exam of the dog to check for hip laxity / hip dysplasia?

Back 38

Ortolani test

Front 39

what is an Ortolani sign

Back 39

a click or pop, representing a subluxation of the coxofemoral joint when performing a Ortolani test for hip laxity / hip dysplasia on a dog

Front 40

what considerations should be made when performing an Ortolani test on a young dog

Back 40

young dogs naturally have some laxity in their coxofemoral joints

Front 41

what are four procedures commonly performed on a dog during a sedated orthopedic examination?

Back 41

1. repeating of specific portion of orthopedic exam
2. radiographic assessment
3. joint tap
4. biopsy

Front 42

what are the three basic types of joints?

Back 42

1. fibrous joints
2. cartilaginous joints
3. synovial joints

Front 43

what type of cartilage is load-bearing

Back 43

hyaline cartilage

Front 44

what comprises the joint capsule?

Back 44

- outer layer made of fibrous connective tissue
- inner layer with a thin subsynovium and a synovium, the latter being in contact with the synovial fluid
- nerves, BVs, and lymphatics interposed between the synovial membranes and the fibrous capsule

Front 45

what are the types of synovial cells and their functions?

Back 45

- Synovial A cells: primarily phagocytic; secrete IL-1 and PGE
- Synovial B cells: fibroblast-like; primarily secretory; secrete hyaluronan

Front 46

what are three types of fibrous joints (and an example of each)?

Back 46

1. syndesmosis (temporohyoid joint)
2. suture (skull)
3. gomphosis (tooth sockets)

Front 47

what are two types of cartilaginous joints (and an example of each)?

Back 47

1. hyaline cartilage / synchondrosis (growth plates)
2. fibrocartilage / amphiarthrosis (mandibular symphysis)

Front 48

what are components of normal synovial joint fluid?

Back 48

- mononuclear cells (synovial cells, monocytes, lymphocytes, PMNs)
- ultrafiltrate of plasma
- secretions of synovial B cells (e.g. hyaluronic acid)

Front 49

what are the three basic functions of synovial fluid?

Back 49

1. lubricate the joint
2. stabilize the joint (shear stress, energy absorption)
3. nutrition (articular cartilage, intra-articular ligaments)

Front 50

what percentage of hyaline cartilage is ECM and what is the rest?

Back 50

90% extracellular matrix; 10% chondrocytes

Front 51

what comprises the extracellular matrix of hyaline cartilage?

Back 51

- water (> 70%)
- collagen
- non-collagenous proteins
- enzymes
- proteoglycans

Front 52

proteins in the articular cartilage collagen matrix:
- structure
- composition
- basic function

Back 52

- high MW brush polymer (and the side chains are brushes)
- core: hyaluronate polymer (a glycosaminoglycan) with aggrecan (a proteoglycan) side-chains
- side-chains: aggrecan (chondroitin sulfate and keratin brushes on a link protein, which serves as core polymer)
- the brushes are negatively charged to provide rigidity to the chain; the polymer itself provides resilience and flexibility to the collagen connective tissue matrix

Front 53

explain how proteoglycans, collagen, and water form a viscoelastic articular cartilage

Back 53

- collagen forms the matrix
- proteoglycans are locked into place by the collagen and form aggregates with hyaluronan
- proteoglycans resist deformation, hold water, and control the transport of molecules and ions
- water flows in and out of the semi-permeable cartilage and gives it the viscoelastic property

Front 54

hyaluronan:
- type of molecule
- typical concentration in synovial fluid
- function

Back 54

- a non-sulfated glycosaminoglycan (high MW amino polysaccharide)
- 0.1 - 5 mg/ml
- provides lubrication as well as nutrition to the joints; gives high viscosity to synovial fluid

Front 55

what advantage does high viscosity give to a synovial joint?

Back 55

- supports transient shear stress
- absorbs some energy generated by movement
- boundary lubrication

Front 56

what are the zones of articular cartilage?

Back 56

- synovial fluid
1. zone 1 - superficial/tangential zone
2. zone 2 - transitional zone
3. zone 3 - radial zone
4. tide mark
5. zone 4 - zone of calcified cartilage

Front 57

zone 1 of articular cartilage:
- name
- structure
- function

Back 57

- superficial / tangential zone
- small, flat chondrocytes and collagen fibrils that line up parallel with the articular surface
- withstands SHEAR STRESS (tension in the plane of the articular surface)

Front 58

zone 2 of articular cartilage:
- name
- structure
- function

Back 58

- transitional zone
- spherical chondrocytes with large collagen fibrils arranged in an intricate 3D matrix
- increased resilience to COMPRESSIVE LOADING

Front 59

zone 3 of articular cartilage:
- name
- structure
- function

Back 59

- radial zone / deep zone
- largest zone; chondrocytes arranged in short columns perpendicular to the joint surface; highest proteoglycan and least water; more rigid matrix that may have partially calcified cartilage (hydroxyapatite crystals)
- increased resilience to compressive loading

Front 60

zone 4 of articular cartilage:
- structure
- function

Back 60

- zone of calcified cartilage
- separated from the preceding zones by the tidemark
- anchors the articular cartilage to the subchondral bone

Front 61

meniscus
'- composition
- seven major functions

Back 61

- composition of fibrocartilage
1. distribution of joint fluid (lubrication)
2. shock absorption
3. load bearing
4. joint congruency
5. stabilization of joint
6. proprioception
7. prevent synovial entrapment

Front 62

what is the term used to describe the reduction of friction in a joint by exudation of fluid from articular cartilage?

Back 62

weeping lubrication

Front 63

ability of joint fluid to change its viscosity based on movement of the joint

Back 63

thixotropy

Front 64

in articular cartilage, how is load resisted (energy dissipated) by:
- collagen fibrils?
- proteoglycans?

Back 64

- collagen: tensile strength
- proteoglycans: compression resistance

Front 65

what are three responses of articular cartilage, when put under a load, that facilitate the structural stability and mobility of the joint?

Back 65

1. they increase contact area (distributes the load)
2. increase joint conformity (stability)
3. exudes a thin gel of concentrated lubricant between the articular surfaces

Front 66

subchondral bone:
- composition
- function

Back 66

- mixture of trabecular and compact bone
- gives structural support to the overlying articular cartilage

Front 67

what is the response of subchondral bone during loading and how does confer stability to the joint?

Back 67

- it bends
- it keeps congruent contact of joint surfaces
- stress dissipation across the joint

Front 68

what are three common contributors to abnormal joint motion?

Back 68

1. ligament rupture
2. developmental or anatomic abnormalities
3. abnormal physiologic loads on cartilage

Front 69

what are three negative consequences of abnormal physiologic loads on articular cartilage?

Back 69

1. fracturing or fissuring of the cartilage matrix
2. disruption of the collagen fibril network
3. cell death

Front 70

Why is rigid internal fixation necessary for fractures involving the articular cartilage?

Back 70

- the reduction of the fracture needs to be as close to the original anatomy as possible
- as such, rigid stabilization is needed during the healing process

Front 71

What is the difference in healing between superficial cartilage defects and full thickness cartilage defects?

Back 71

- superficial defects (that do not extend to the bone) do not elicit an inflammatory response and heal by chondrocyte proliferation and new matrix production
- full thickness defects (those that extend to the subchondral bone) elicit an inflammatory response, which produces fibrin and collagen; the defect fills with fibrocartilage

Front 72

inflammation of the biceps tendon and surrounding sheath

Back 72

bicipital tenosynovitis

Front 73

what are two radiographic signs for bicipital tenosynovitis in the dog?

Back 73

1. intertubercular groove sclerosis
2. bicipital tendon mineralization

Front 74

what is the end stage of septic arthritis?

Back 74

subchondral bone lysis

Front 75

what is the most common etiology for septic arthritis?

Back 75

bacterial infection

Front 76

what type of septic arthritis would bacteremia produce?

Back 76

septic polyarthritis

Front 77

what are two common etiologies for mono-articular septic arthritis?

Back 77

1. puncture
2. surgery

Front 78

what are three common radiographic signs of severe septic arthritis in the stifle?

Back 78

1. IC ST swelling
2. obliteration of the caudal fascial stripe
3. lysis of bone

Front 79

what are two radiographic signs of an aggressice joint lesion?

Back 79

1. intracapsular soft tissue swelling
2. permeative/punctate/moth-eaten lysis of multiple bones in the joint

Front 80

what are the three components of the syndrome of erosive polyarthritis?

Back 80

1. sub-chondral erosions
2. joint subluxation
3. intracapsular soft tissue swelling

Front 81

what is the most common site for erosive polyarthritis in the small animal and how does it appear radiographically?

Back 81

- most commonly at the distal extremity (metacarpal/metatarsal-phalangeal joints)
- whereas the articular surfaces of the metacarpal/metatarsal bones normally have a "dumbbell" appearance, in erosive polyarthritis, they have a "pencil" appearance
- intracapsular soft tissue swelling (consistent with an aggressive joint lesion)

Front 82

what are two common differentials for erosive polyarthritis?

Back 82

1. rheumatoid arthritis
2. feline non-infectious polyarthritis

Front 83

describe the radiographic findings of erosive polyarthritis from onset and as it gets worse

Back 83

1. starts with intracapsular soft tissue swelling with no apparent bony lysis
2. incarease coarseness to the trabecular pattern of affected bones may be noted
3. lucent, cyst-like lesions in the subchondral bone at the joint capsule attachments and later on the articular margins
4. cystic lesions progress to irregular erosion of the subchondral bone and marked destruction of the joint surface
5. subluxation and luxation of joints due to destruction of the ligaments

Front 84

what are the radiographic characteristics of non-erosive polyarthritis?

Back 84

- normal bone
- intracapsular soft tissue swelling
- polyarticular (may be nonoarticular early)

Front 85

what are the most common joints for non-erosive polyarthritis?

Back 85

tarsus, carpus, stifle

Front 86

what is the main differential for non-erosive polyarthritis?

Back 86

lupus

Front 87

what are six locations for joint associated tumors from most common to least common?

Back 87

1. stifle (most common)
2. elbow
3. shoulder
4. carpus
5. tarsus
6. hip (less common)

Front 88

what are four differentials for joint associated tumors?

Back 88

synovial cell sarcoma, histiocytic sarcoma, synovial myxoma, undifferentiated sarcomas

Front 89

what is a common sequela to a joint associated tumor of the stifle

Back 89

cranial cruciate ligament tear

Front 90

a lesion appearing similar to erosive polyarthritis, but only of a single joint is likely what?

Back 90

joint associated tumor (synovial cell sarcoma)

Front 91

describe the radiographic signs of a joint associated tumor

Back 91

1. severe, lobulated intracapsular soft tissue swelling
2. lysis of bones in the joint

Front 92

what are two differentials for MONOarticular intracapsular soft tissue swelling WITHOUT bone lysis

Back 92

1. effusion (DJD, trauma, hemarthrosis, etc.)
2. synovitis

Front 93

what are two differentials for MONOarticular intracapsular soft tissue swelling WITH bone lysis

Back 93

1. septic arthritis
2. joint associated tumor

Front 94

what are two differentials for POLYarticular intracapsular soft tissue swelling WITHOUT bone lysis

Back 94

1. effusion (DJD, hemarthrosis, etc.)
2. non-erosive polyarthritis

Front 95

what are two differentials for POLYarticular intracapsular soft tissue swelling WITH bone lysis

Back 95

1. erosive polyarthritis (most common SA)
2. septic arthritis (most common LA)

Front 96

what are three signs that define the syndrome of osteoarthritis?

Back 96

1. articular cartilage degeneration
2. marginal bone hypertrophy
3. synovial membrane changes

Front 97

what are two common synonyms for osteoarthritis?

Back 97

DJD, osteoarthrosis

Front 98

what is the end stage of osteoarthritis?

Back 98

ankylosis

Front 99

what are the two basic types of osteoarthritis?

Back 99

primary (unknown cause, rare) and secondary (known cause, most common)

Front 100

what are five causes of secondary osteoarthritis?

Back 100

1. previous trauma
2. joint instability
3. inflammation
4. developmental conditions
5. joint incongruency

Front 101

what are the two basic physiological abnormalities that can lead to cartilage breakdown and osteoarthritis?

Back 101

1. abnormal stresses on the cartilage
2. abnormal cartilage

Front 102

what are five causes of abnormal stress that can lead to failure of normal articular cartilage?

Back 102

1. developmental/anatomic abnormalities
2. obesity
3. microfractures and bone remodeling
4. trauma
5. loss of joint stability

Front 103

what are five causes of abnormal articular cartilage that will fail under normal stress?

Back 103

1. genetic and metabolic disease
2. aging
3. administration of toxins (e.g. enrofloxacin)
4. inflammation
5. immune responses

Front 104

in osteoarthritis, what pathophysiologic changes are caused by cartilage fibrillation/fissuring?

Back 104

- cellular alteration
- release of inflammatory mediators

Front 105

when cartilage is damaged in osteoarthritis, how does it change on the molecular level?

Back 105

degradation of collagen and proteoglycan

Front 106

describe the pathogenesis of how an abnormal stress on articular cartilage leads to pain and lameness in osteoarthritis

Back 106

abnormal stress → collagen and proteoglycan destruction → loss of matrix components and decreased cartilage synthesis → breakdown of articular cartilage → pain and lameness

Front 107

describe the two basic theories of why cartilage breaks down under stress overload.

Back 107

-Theory A: (physiologic) cell injury leads to a degradative response, releasing enzymes that degrade cartilage
-Theory B: (mechanical) a biomaterial failure leads to mechanical failure of the collagen network and unravelling of proteoglycan

Front 108

what are seven (variable) clinical signs of osteoarthritis?

Back 108

1. stiffness
2. exercise intolerance
3. lethargy
4. joint effusion
5. lameness
6. pain
7. disuse atrophy

Front 109

what are four common clinical findings of osteoarthritis on physical examination?

Back 109

1. decreased joint range of motion
2. crepitus
3. muscle atrophy
4. muscle asymmetry

Front 110

what are six common radiographic findings for osteoarthritis?

Back 110

1. osteophytes and enthesiophytes
2. joint effusion
3. subchondral bone sclerosis
4. bone remodeling
5. thickening of periarticular soft tissues
6. cartilage destruction

Front 111

what are the five basic principles of treatment of joint disease?

Back 111

1. weight management
2. nutritional supplementation
3. exercise moderation
4. physical rehab
5. NSAIDs and other medical therapies

Front 112

what is the most common nutritional supplement for osteoarthritis? How does this work?

Back 112

ω-3 fatty acids decrease the amount of arachidonic acid in the cell membranes and therefore decrease the production of COX/lipoxygenase inflammatory mediators

Front 113

what is a DMOA (with regards to nutritional supplements)

Back 113

"disease modifying osteoarthritic agent"; a chondroprotective nutritonal supplelement

Front 114

what are four proposed mechanisms by which chondroprotectives/DMOA supplementation is said to provide their beneficial effects?

Back 114

1. promote cartilage matrix synthesis
2. slow cartilage degradation
3. decrease breakdown products
4. anti-inflammatory effects

Front 115

name five different chondroprotectives for joint disease

Back 115

1. chondoitin sulfate
2. Polysulfated glycosaminoglycans
3. hyaluronic acid
4. mangnese
5. vitamin C

Front 116

what is a possible complication of PSGAG (polysulfated glycosaminoglycans)

Back 116

they have heparin-like activity and can cause thrombocytopenia

Front 117

in treating joint disease, what does the term "controlled exercise" mean?

Back 117

rehabilitation to correct abnormalities with gradual introduction and consistent activity. Inactivity and extreme activity may worsen the situation.

Front 118

in the treatment of joint disease, what are five goals of physical rehabilitation therapy?

Back 118

1. increase strength and endurance
2. increase joint ROM
3. decrease edema
4. promote tissue repair/metabolism
5. decrease muscle spasms and pain

Front 119

what are four severe complications of NSAID administration?

Back 119

1. GI ulcers/upset
2. nephrotoxicity
3. hepatotoxicity (carprofen; especially in labradors)
4. keratoconjunctivitis siccs (etodolac)

Front 120

what are three commonly prescribed COX-2 NSAIDs for treatment of joint disease?

Back 120

1. carprofen
2. meloxicam
3. deracoxib

Front 121

what are five contraindications for the use of NSAIDs in the treatment of joint disease?

Back 121

1. renal disease
2. gastric ulcers
3. bleeding disorder
4. hepatic disease
5. if patient is on a corticosteroid

Front 122

what type of analgesic should ntop be combined with NSAIDs

Back 122

corticosteroids

Front 123

name four analgesics that can be combined with NSAIDs in the treatment of joint disease and what class of drugs they are.

Back 123

1. tramadol - an opiate
2. gabapentin - Ca channel blocker
3. amantadine - NMDA receptor antagonist
4. amitriptyline - tricyclic antidepressant

Front 124

what are four basic types of medical magament techniques to treat septic arthritis (in order of least sever to most severe cases)

Back 124

1. antimicrobials
2. surgical/arthroscopic lavage
3. drain placement
4. open joint management

Front 125

what is the proper method of using antimicrobials to treat septic arthritis?

Back 125

- give antibiotic immediately after joint fluid samples are taken
- alter the antibiotic based on culture/susceptibility testing
- treat 4-6 weeks; continue 2 weeks after resolution of clinical signs

Front 126

what drugs are commonly used to treat (sterile) non-erosive polyarthritis?

Back 126

-corticosteroids such as prednisone
- immunosuppressives (azathioprine, cyclosporine, cyclophosphamide)

Front 127

what are two common treatments for rheumatoid arthritis?

Back 127

1. immunosuppressive drugs
2. arthrodesis (surgical joint immobilization)

Front 128

what distinguishes calcified cartilage from hyaline cartilage?

Back 128

- matrix calcified and is invaded by blood vessels
- osteoid is produced, scaffold for bone formation

Front 129

before skeletal maturity, and during growth, what must be true of cartilage production and bone replacement?

Back 129

they must be equal so that the growth plate is maintained

Front 130

what is the term for the tissue supplied by blood vessels to cartilage during endochondral ossification?

Back 130

osteogenic granulation tissue

Front 131

what is the most common site for OCD? What other two places is OCD less commonly found?

Back 131

- most common: articular-epiphyseal complex
less common: metaphyseal and apophyseal growth plates

Front 132

what is the basic process of endochondral calcification?

Back 132

orderly calcification of cartilage matrix → vascular invasion → deposition of osteogenic granulation tissue → replacement of cartilage by bone tissue

Front 133

define OCD in one sentence

Back 133

A developmental orthopedic disease, caused by the disruption of endochondral ossification, characterized by a focal area of developing cartilage at the osteochondral junction that fails to calcify and instead thickens and degenerates.

Front 134

what are the two basic processes of endochondral ossification that DON'T happen, that leads to OCD?

Back 134

- failure of matrix calcification
- lack of vascular ingrowth

Front 135

why do areas of cartilage in OCD become necrotic?

Back 135

because the thickened cartilage has poor diffusion of nutrients from synovial fluid

Front 136

since in OCD, there is a failure of calcification and vascular invasion, what type of cartilage does the OCD lesion represent?

Back 136

it becomes more like articular cartilage, as opposed to calcified cartilage that will turn into bone

Front 137

separation between calcified and non-calcified layers of joint cartilage

Back 137

tidemark

Front 138

in OCD, at what location does the fissure develop that breaks off into a flap?

Back 138

at the tidemark

Front 139

what are the three fates of a cartilage lesion in OCD?

Back 139

1. reattachment (very rare)
2. vertical fracture of articular cartilage may form
3. detachments of fragments, which become joint mice

Front 140

theoretically, how could a cartilage flap reattach to subchondral bone?

Back 140

a bleeding defect beings in mesenchymal cells

Front 141

in OCD, why might a vertical fracture of articular cartilage form? What are clinical signs associated with this? Why will this fracture not heal?

Back 141

- fracture caused by motion of flap against the cartilage during weight-bearing motion
- irritation causes synovitis, pain, lameness, and OA
- the fracture does not heal because of the synovial fluid interposed in the fracture

Front 142

in OCD, why is a joint mouse often larger than the lesion from whence it came?

Back 142

the cartilage flap was not dead when it broke off; it continued to enlarge due to nutrition from synovial fluid

Front 143

what are six basic etiologic factors leading to OCD?

Back 143

1. trauma
2. anatomical factors
3. hormonal factors
4. heredity (familial, breed predisposition)
5. over nutrition (especially excess dietary Calcium)
6. rapid growth rates

Front 144

how does trauma contribute to the development of OCD?

Back 144

- while ischemia of subchondral bone has been shown as a cause in humans, it does not appear to be a cause in dogs
- biomechanical stress (repeated microtrauma) most likely the cause of flap formation

Front 145

how do anatomical factors of contribute to OCD in the canine humeral head?

Back 145

the cartilage is particularly thick in this location. Since the caudomedial aspect of this cartilage develops more slowly, it is susceptible to microtrauma from the glenoid

Front 146

how do hormonal factors contribute to OCD?

Back 146

- excess growth hormones (particularly somatotropin and thyrotropin) contribute to thickening of the cartilage
- testosterone (esp. in males) is synergistic with growth hormones and delays endochondral ossification
- in contrast, estrogen encourages cartilage calcification

Front 147

why are males overrepresented for OCD?

Back 147

because testosterone promotes growth of cartilage and delays endochondral ossification, whereas estrogen encourages cartilage calcification

Front 148

what dog breed and breed-types are most susceptible to OCD?

Back 148

Great Danes, St. Bernards, Labradors, Rottweilers, and other large and giant breeds, especially those with adult weights > 20kg

Front 149

in which species does ischemia a cause of OCD and why does this lead to OCD? What is the proposed reason why ischemia occurs?

Back 149

- pigs, horses, humans
- leads to cartilage necrosis
- may be related to rapid growth rate

Front 150

for suspected OCD, why should you always radiograph both joints?

Back 150

because OCD is very often bilateral, although lameness may appear to be only on one limb.

Front 151

where are the four most common sites of OCD in the dog, and what is the prognosis for lameness after medical and/or surgical intervention?

Back 151

1. shoulder - good (75%)
2. elbow - guarded
3. stifle - guarded
4. hock - poor

Front 152

what is the common site of OCD in the shoulder?

Back 152

caudal aspect of the humeral head

Front 153

what is the common site of OCD in the elbow?

Back 153

distal trochlear ridge of the medial aspect of the humeral condyle

Front 154

what is the common site of OCD in the stifle?

Back 154

medial aspect of the lateral femoral condyle

Front 155

what is the common site of OCD in the hock?

Back 155

usually on the plantar aspect of the medial trochlear ridge of the talus

Front 156

comment on the incidence (male:female and how often bilateral) in OCD of the
- shoulder
- elbow
- stifle
- hock

Back 156

- shoulder: males 2:1-6:1; 20-85% bilateral
- elbow: males 2:1; 20-50% bilateral
- stifle: males 3:1; 72% bilateral
- hock: males=females; 40% bilateral

Front 157

what two dog breeds are overrepresented for OCD of the hock?

Back 157

Rottweilers and Labradors

Front 158

what is a DMOA?

Back 158

disease modifying osteoarthritic agent

Front 159

generally, when is medical management preferred over surgery for treatment of OCD?

Back 159

- young age (< 7 months old)
- in OCD of the hock, older dogs with sever OCD (due to poor prognosis of surgery)
- small radiographic lesions
- no joint mice
- no clinical pain

Front 160

generally, when is surgical treatment indicated for OCD?

Back 160

- > 8 months of age
- flap/joint mouse present
- persistent lameness (> 6 weeks)
- large lesion

Front 161

what are four aspects for conservative medical treatment of OCD?

Back 161

1. strict cage rest for 4-6 weeks
2. NSAIDs
3. DMOA supplementation (disease modifying osteoarthritic agents)
4. restricted diet (calories and calcium)

Front 162

In mild-moderate cases of OCD, why is it sometimes preferable to just go ahead and do surgery instead of trying to manage it conservatively?

Back 162

because it has been shown that surgery allows more rapid return to function and minimizes the development of OA

Front 163

what are the three basic aims of surgery to treat OCD?

Back 163

1. remove flap/joint mice
2. remove non-adherent cartilage in the periphery of the lesion
3. stimulate the defect to heal by fibrocartilage formation (curettage, forage, abrasion arthroplasty)

Front 164

what are the two basic surgical approaches to treat OCD?

Back 164

1. arthrotomy
2. arthroscopy

Front 165

with regards to OCD, what is the OATS surgical procedure?

Back 165

- osteochondral autograft transfer system
- transfer articular cartilage and subchondral bone from one site in the body to the other in the same patient

Front 166

what are four complications of joint surgery?

Back 166

1. seroma
2. wound dehiscence
3. infection
4. chronic lameness

Front 167

what are the three basic radiographic findings of an osteochondritic lesion?

Back 167

1. intracapsular soft tissue swelling
2. subchondral defect/flattening of articular surface
3. sclerosis surrounding the OC lesion

Front 168

why might a flap from OCD not be seen on a radiograph

Back 168

because to be seen it requires mineralization; cartilage silhouettes with other soft tissue

Front 169

what is the average age range of osteochondrosis in dogs
- in the shoulder?
- in the stifle?
- in the elbow?
- in the hock?

Back 169

- shoulder: 6-9 months
- stifle: 6-10 months
- elbow: 6-8 months
- hock: 6-12 months

Front 170

when performing radiography on a shoulder for osteochondrosis, and it appears unilateral, what should you do to make sure it is only unilateral?

Back 170

perform a rotated limb view to expose more of the caudal humeral head

Front 171

what view is best to radiographically visualize OCD of the shoulder?

Back 171

lateral or rotated lateral

Front 172

what views are best to radiographically view OCD of the stifle?

Back 172

lateral and cranial-caudal

Front 173

what normal anatomic feature of the stifle can be confused for osteochondrosis?

Back 173

the extensor fossa on the lateral femoral condyle

Front 174

what views are best to radiographically view OCD of the hock?

Back 174

cranial-caudal; lateral; and oblique for the lateral trochlear ridge (due to superimposition of the talus)

Front 175

where is intracapsular soft tissue swelling usually seen radiographically in the hock of the young dog that may lead you to suspect osteochondrosis?

Back 175

on a lateral view:
- dorsal to the calcaneus/caudal to the tibia
- dorsal to the trochlea of the talus/cranial to the tibia

Front 176

what are four conditions that encompass the term "elbow dysplasia"?

Back 176

1. ununited anconeal process
2. fragmented medial coronoid process (of the ulna)
3. osteochondrosis
4. premature radius/ulna physis closure

Front 177

what view is best to radiographically view osteochondrosis of the elbow?

Back 177

cranial-caudal projection is the only good view

Front 178

what radiographic view is best to visualize an ununited anconeal process?

Back 178

flexed lateral

Front 179

anconeal process:
- when should it unite with the ulna?
- if ununited, is this most often a unilateral or bilateral condition?
- what breed of dog is predisposed to this condition?

Back 179

- should unite by 5 months of age
- often bilateral
- German Shepherd Dog

Front 180

what is the best method to visualize a fragmented medial coronoid process of the ulna?

Back 180

CT

Front 181

what is the most common developmental elbow disorder?

Back 181

fragmented medial coronoid process

Front 182

radiographically, besides the primary lesion, what other lesions are associated with a fragmented medial coronoid process of the ulna?

Back 182

- osteophytes on the anconeal process and radial head
- sclerosis of the trochlear notch of the proximal ulna

Front 183

how does growth of the ulna compare to that of the radius?

Back 183

the ulna has only one physis (distal to the elbow) whereas the radius has two physes; so the growth from one physis must equal the growth of the other two

Front 184

what are three results of a premature ulnar physis closure?

Back 184

1. lateral deviation and rotation of the manus (valgus)
2. radius curvus
3. humeroulnar subluxation

Front 185

what is a common procedure to prevent limb deformity in the case of a premature ulnar physis closure?

Back 185

ulnar ostectomy

Front 186

what condition of the proximal radioulnar joint can cause elbow dysplasia?

Back 186

a step misalignment of the radial head and the medial coronoid process of the ulna

Front 187

what is the usual end result of a premature radial physis closure?

Back 187

humeroradial subluxation

Front 188

signalment for panosteitis:
- age
- dog breeds and breed types
- sex

Back 188

- most common 5-18 months, but can be seen in middle-aged dogs
- medium to large breeds; German Shepherd Dogs and Basset Hounds
- male > female

Front 189

what are two early radiographic signs of panosteitis?

Back 189

- increased medullary opacity, usually seen in the distal diaphysis of the femur near the nutrient foramen
- blurring of the trabecular pattern

Front 190

what are two radiographic signs of advanced panosteitis

Back 190

- patchy, delineated medullary opacities
- solid (smooth/lamellar) periosteal reaction on the adjacent cortex

Front 191

signalment for HOD:
- age
- dog breeds and breed types
- sex

Back 191

- 3-5 months
- Weimaraner and Great Dane; other large, rapidly-growing dogs
- males > females

Front 192

what are the most commonly affected bones in HOD?

Back 192

radius, ulna, and tibia

Front 193

what are three radiographic signs of HOD?

Back 193

1. soft tissue swelling adjacent to physis
2. linear, irregular lysis adjacent and parallel to the physis that gives the appearance of a "double physeal line"
- marked metaphyseal periosteal reaction due to sub-periosteal hemorrhage

Front 194

a form of osteochondrosis that results from temporary inadequate blood supply to the metaphysis

Back 194

retained cartilaginous core

Front 195

viewed radiographically, a wedge or conical shape in the metaphysis of the ulna

Back 195

retained cartilaginous core

Front 196

what are three synonyms for panosteitis?

Back 196

1. eosinophilic osteomyelitis
2. eosinophilic panosteitis
3. enostitis

Front 197

signalment for panosteitis:
- age
- dog breed and breed type
- sex

Back 197

- juvenile dogs
- German Shepherd Dogs, Basset Hounds, large and giant breed dogs
- males > females; females @ 1st estrous cycle

Front 198

what type of bones and what part of the bones are affected by panosteitis?

Back 198

- long bones of the appendicular sksleton
- diaphysis and metaphysis

Front 199

what are seven etiologies proposed for panosteitis?

Back 199

1. STRESS (e.g. during 1st estrous cycle)
2. eosinophilia (rare)
3. microorganisms/viruses/parasites
4. genetic
5. allergy
6. metabolic
7. autoimmune

Front 200

what is the pathogenesis of panosteitis?

Back 200

- loss of medullary adipose tissue, followed by fibrous proliferation, intramembranous ossification, and osteoclastic removal of trabeculae
- periosteal proliferation and cortical changes seen in more severe cases
- returns to normal ~60-90 days (can last up to 190 days)

Front 201

which part of the long bone is NOT affected by panosteitis?

Back 201

the epiphysis

Front 202

describe the lameness associated with panosteitis
- onset
- severity
- persistence
- effect of exercise and rest
- location

Back 202

- acute onset
- mild to moderate weightbearing lameness
- persists 2-14 days
- not influenced by exercise or rest
- shifting leg lameness that usually doesn't return to the same leg

Front 203

what five bones are most commonly affected by panosetitis in the order of prevalence?

Back 203

1. ulna (most common)
2. radius
3. humerus
4. femur
5. tibia

Front 204

what are some signs from the patient's history that might point to panosteitis?

Back 204

1. listlessness
2. reluctance to move
3. lameness (acute onset)
4. anorexia
5. no concurrent HX of trauma

Front 205

what are two clinical signs of lameness on physical examination?

Back 205

1. pain on deep palpation of bone (mild to extremely painful)
2. mild-moderate weightbearing lameness

Front 206

what type of imaging technique would be the best for diagnosing panosteitis?

Back 206

bone scan

Front 207

what are five differentials for panosteitis?

Back 207

1. OCD
2. hip dysplasia
3. osteomyelitis
4. Nutritional secondary hyperparathyroidism
5. trauma (strain/sprain, fracture, luxation)

Front 208

what are four ways to medically manage panosteitis?

Back 208

1. N.B. it is self-limiting
2. control pain and inflammation
3. exercise restriction
4. ± weight reduction

Front 209

what is a common clinical sign of a retained cartilagenous core in the distal femur

Back 209

genu valgum (knees pushed together)

Front 210

a "flame" shape to the distal ulnar physis may indicate which disease?

Back 210

retained cartilaginous core

Front 211

what is a common surgical procedure to prevent/treat radius curvus in severe cases of a retained cartilagenous core in the ulna?

Back 211

ulnar ostectomy

Front 212

what are three synonyms for hypertrophis osteodystrophy?

Back 212

1. canine skeletal scruvy
2. idiopathic osteodystrophy
3. Barlow's disease

Front 213

what are four clinical signs of HOD on PE?

Back 213

1. (per)acute mild NON-WEIGHTBEARING lameness
2. pain on palpation
3. fever > 104 °F
4. swollen/warm/painful distal limb

Front 214

what type of bone and where specifically in the bone does HOD occur?

Back 214

the metapheal side of the active physis on a long bone

Front 215

describe the timing of pain/lameness associated with HOD

Back 215

- episodic
- symtpmatic ≈ 1 week
- multiple recurrences uncommon, 1-6 weeks apart

Front 216

name six places where HOD can occur

Back 216

1. distal radius
2. distal ulna
3. tibia
4. TMJ
5. costochondral junction
6. scapula

Front 217

what are five proposed etiologies for HOD?

Back 217

1. abnormal vitamin C metabolism
2. excessive vitamin/mineral supplementation
3. vacciation
4. genetic
5. immune-related

Front 218

what abnormalities can be found in the affected area of HOD?

Back 218

1. disrupted trabeculae
2. hemorrhage
3. hemosiderin deposits
4. necrotic trabeculae
5. inflammatory cells
6. resorption of trabeculae
7. neutrophilic infiltration

Front 219

what are the characteristics of the synovial fluid with HOD?

Back 219

- ↑ volume (1-3 ml)
- transparent, straw-colored
- normal viscosity
- ↑PMN

Front 220

what are three DDx for HOD?

Back 220

1. septic arthritis
2. septic physitis
3. panosteitis

Front 221

what is a pathognomonic radiographic sign for HOD?

Back 221

a "double-physis"

Front 222

what are some clinical signs for peracute HOD?

Back 222

- more severe than normal HOD
- < 1 day of refusal to stand
- dehydration
- malaise
- depression
- severe pain on gentle palpation of swollen areas
- prolonged recumbency
- anorexia
- hyperthermia (106 °F)

Front 223

how is mild-moderate HOD treated?

Back 223

- medical management (not Sx)
- N.B. self-limiting disease
- NSAIDs
- correct diet
- ± antibiotics

Front 224

how is severe HOD treated?

Back 224

- a short course of IV short-acting corticosteroids
- supportive care

Front 225

how is peracute HOD treated?

Back 225

- injectible corticosteroids for a few days
- IV fluids
- force feeding
- well padded bedding
- regular turning

Front 226

what is a more descriptive synonym of Perthes' disease

Back 226

avascular necrosis of the femoral head / neck

Front 227

what type of dogs are affected by Perthes' diesase? Name a specific breed particularly overrepresented.

Back 227

toy and miniature breed dogs. Manchester terrier.

Front 228

what are the three basic stages of Perthes' disease?

Back 228

1. ischemia (necrosis)
2. early repair stage
3. advanced repair stage

Front 229

in Perthes' disease, what are two major effects of disruption of the blood supply? How are chondrocytes affected? How is endochondral ossification affected?

Back 229

1. empty osteocyte lacunae
2. thickening of metaphyseal trabeculae
- normal chondrocytes
- no effect on endochondral ossification

Front 230

in the early repair stage of Perthes' disease, what is the major morphological change of bone?

Back 230

collapse of subchondral bone causes a flattening of the femoral head

Front 231

in the early repair stage of Perthes' disease, in what three ways does the cartilage change?

Back 231

1. clefts and fissures in the articular cartilage due to collapse of the subchondral bone
2. thickening of the articular cartilage
3. invasion of physeal cartilage with fibrovascular repair tissue

Front 232

in the early repair stage of Perthes' diesase, what two cardiovascular effects occur?

Back 232

1. revascularization of the epiphysis
2. resorption of necrotic bone marrow debris and dead trabeculae

Front 233

in the advanced repair stage of Perthes' disease, describe the major alterations in the joint that will lead to progressive osteoarthritis

Back 233

1. loss of normal shape of the femoral head
2. markedly thickened articular cartilage

Front 234

in general, why are small dogs thought to be more susceptible to Perthes' disease than larger dogs?

Back 234

because they have a more superficial blood supply, which can more easily be interrupted

Front 235

describe the arterial anatomy of the femoral head

Back 235

The lateral circumflex a., medial circumflex a., and caudal gluteal a. anastamose to form a vascular ring around the femoral neck

Front 236

describe a typical HX (3 steps) that illustrates the progression of Perthes' disease

Back 236

1. slow onset weight-bearing lameness
2. worsens over 6-8 wk
3. progresses to acute lameness

Front 237

what are five clinical signs on PE of Perthes' disease?

Back 237

1. lameness
2. pain
3. decreased ROM
4. muscle atrophy
5. crepitus

Front 238

what are five ragiographic signs of Perthes' disease?

Back 238

1. deformity of the femoral head
2. SHORTENING or LYSIS of the femoral neck
3. focal areas of decreased bone opacity in the femoral epiphysis
4. femoral neck fracture
5. osteoarthritis (not common in a 4-5mo animal)

Front 239

what is the most common DDx for Perthes' disease?

Back 239

medial patellar luxation

Front 240

what are three DDx for Perthes' disease?

Back 240

1. Medial patellar luxation
2. trauma (physeal, coxofemoral luxation, femoral head or neck fracture)
3. muscle strain or sprain

Front 241

when is surgical treatment indicated for Perthes' disease?

Back 241

if radiographic changes are evident

Front 242

what are three methods for conservative treatment of Perthes' diesase?

Back 242

1. NSAIDs
2. restricted activity for 2 months in a nonweight bearing sling
3. non-weight bearing exercises such as swimming

Front 243

what are two common surgical options to treat Perthes' disease?

Back 243

1. femoreal head and neck ostectomy
2. total hip replacement

Front 244

what is an FHO surgery?

Back 244

femoral head and neck ostectomy

Front 245

what are some indications for FHO surgery?

Back 245

(femoral head and neck ostectomy)
'- Perthes' disease
- DJD from hip dysplasia
- acetabular and femoral head/neck fractures
- chronic luxation of the hip
- chronic osteoarthritis of any cause
- when conservative treatment has failed (quality of life issue; last resort before amputation)

Front 246

what are the two basic cuts that are made in a FHO surgery?

Back 246

1. create a fossa to expose the neck of the femur, separating it from the greater trochanter.
2. cut from the medial aspect of the greater trochanter to the lesser trochanter, including the entire neck and head in the cut. Don't cut the greater trochanter.

Front 247

how long after FHO surgery is swimming and other exercise encouraged?

Back 247

by 2 weeks

Front 248

what are four important factors that determine the prognosis of FHO surgery?

Back 248

1. post-operative rehab
2. surgical skill
3. activity of the dog (need exercise ASAP after Sx!)
4. muscle atrophy (the more muscle, the better)

Front 249

how can you minimize the impact of muscle atrophy on the prognosis of post-operative limb function?

Back 249

pre-operative PT to build muscle mass

Front 250

why, in a normal animals would you see a flattened region on the femoral head?

Back 250

it is the fovea capitis, the site of attachment of the round ligament of the head of the femur

Front 251

when assessing hip dysplasia, what part of the coxofemoral joint do you look at?

Back 251

the cranial 3rd of the acetabular margin

Front 252

what are the three things that you need to look at radiographically to diagnose hip dysplasia?

Back 252

1. dorsal acetabular rim coverage (≥50%)
2. congruity along the cranial 1/3rd of the joint
3. DJD

Front 253

what are two early radiographic signs of hip dysplasia?

Back 253

1. ostephyte formation on the caudal aspect of the femoral neck (Morgan line)
2. coxofemoral hip laxity

Front 254

what is the proper radiographic positioning for the extended standard view of the pelvis, to diagnose hip dysplasia?

Back 254

- VD view
- pull legs down and rotate legs inward
- entire pelvis and both femora, though the stifle

Front 255

what are three things to look for when evaluating whether your extended pelvic radiograph was positioned correctly?

Back 255

1. similar contour of the wings of the ilia
2. obturator foramina should be symmetrical in shape
3. the patellae should be located in the center of the femora (trochlear groove)

Front 256

what are the two standardized tests for hip dysplasia evaluation?

Back 256

1. OFA test
2. PennHip test

Front 257

what are three requirements for submission of a radiograph to the OFA for evaluation of hip dysplasia?

Back 257

1. extended leg VD
2. paperwork for the animal (e.g. AKC)
3. patient must be ≥2 years old

Front 258

what are two reasons why an extended leg VD is suboptimal for evaluating hip dysplasia?

Back 258

1. twisting of the joint capsule will force the femoral head into the acetabulum, thus artificially decreasing joint space
2. muscular tension in the unsedated patient will do the same

Front 259

what three views are required for a PennHip hip dysplasia submission?

Back 259

1. extended leg VD
2. Compressed VD
3. distraccted VD