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108 Cards in this Set
- Front
- Back
How much bone loss to detect lysis? |
--30-50% |
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Horses do not make a lot of ______, so they have less ______ reaction and ______. |
--bone --periosteal rxn, callus |
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Markers are always _____ or _____. |
Lateral or dorsal |
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The most superimpositon of structures is always? |
--in direction of x-ray beam |
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Flexed lateromedial views are important for evaluating ____ ____. |
joint margins |
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Where are four lesion locations? |
intracapsular periarticular periosteal extracapsular |
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What are the Roentgen signs? |
size shape location margin number opacity |
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Aggressive bone lesion features? (5) |
lysis cortical destruction periosteal proliferation long zone of transition soft tissue swelling |
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Benign bone lesion features? |
well-defined margins periarticular bony proliferation enthesophytes |
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Osteochondrosis/OCD is caused by? |
failure of endochondral ossification (less bone) |
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Is osteochondrosis inflammatory? |
not inflammatory! |
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OCD most commonly affects _____, _____, ______ in horse. |
tarsus stifle fetlock |
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What is a DIRT lesion? |
OCD on distal intermediate ridge of tibia |
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What are the two best views of DIRT? |
lateromedial DMPLO |
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If DIRT lesion is present, what should you do? |
radiograph the other tarsus (often bilateral) |
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Which parts of the stifle are most often affected by OCD? |
lateral trochlear ridge medial femoral condyle |
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OCD in the stifle is often accompanied by what lesion? |
subchondral cyst |
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OCD predisposes for what disease later in life? |
osteoarthritis |
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Osteomyelitis is a _______, _______ bone lesion. |
polyostotic, aggressive |
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Osteomyelitis occurs frequently in ______ animals, often via _____ ____ from another infection. |
young animals hematogenous spread |
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Osteomyelitis in mature animals is often secondary to _____, ______. |
trauma, wounds |
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What is 'bone spavin'? |
distal tarsal osteoarthritis |
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Osteoarthritis is an _______ process for many ______ diseases. |
endstage process, underlying diseases |
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Osteoarthritis is a chronic, ______, ______ disease. |
chronic, progressive, degenerative |
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OCD, septic arthritis, articular fractures, poor conformation, and ligamentous instability can all cause? |
--osteoarthritis |
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Characteristics of OA? (4) |
periarticular bony proliferation (osteophytes) well-defined margins narrow joint space subchondral bone sclerosis |
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Laminitis disease process? |
--inflammation/ischemia to hoof wall --loss of interdigitation of epidermal and dermal laminae |
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Laminitis is most often secondary to ______ _____ or ______ _____. |
--systemic illness (sepsis, vasculitis) --concussive injury (fracture in contra hoof) |
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Which conditions predispose to laminitis? |
--obesity, endocrinopathy, corticosteroid admin. |
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Developmental/acute laminitis is visible on rads. T/F? |
false--acute laminitis is NOT visible on rads |
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Chronic laminitis is visible on rads. T/F? |
true--chronic laminitis is visible on rads |
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What are the radiographic signs of laminitis? |
--displaced distal phalanx, rotation and sinking |
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Define rotation. How is this detected on rads? |
palmar deviation of distal phalanx dorsal hoof wall will be thicker distally than proximally |
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Define sinking. How is this detected on rads? |
dorsal hoof wall >20mm thickness (uniform) |
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What is founder distance? |
distance between extensor process and coronary band. |
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Why might a secondary infection occur with laminitis? |
If line of epidural/dural laminae separation extends to the sole, could allow infection. |
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Chronic remodeling due to laminitis. What does this look like? |
new bone formation along dorsal aspect of P3 mild, persistent rotation of P3 "ski-tip" |
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What is reverse inclination? |
P3 palmar processes are closer to the sole than tip of P3. Long toe, low heel. |
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Which disease is indicated if lameness substantially improves with palmar digital nerve block? |
navicular bone disease |
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Navicular bone = ______ sesamoid bone |
distal sesamoid bone |
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Which radiographic view is best for diagnosis of navicular disease? Which is second best? |
--skyline view palmaroproximal-palmarodistal oblique --dorso-65-proximal to palmarodistal oblique |
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What are the radiographic signs of navicular bone disease? |
loss of corticomedullary definition due to medullary sclerosis, irregular margins, lucency of flexor cortex, enlarged synovial invaginations |
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How do synovial invaginations change with navicular disease? |
increased size/number, abnormal shape (lollipops) |
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Navicular disease prognosis is guarded if this occurs. |
Mineralization of DDF tendon due to damage/necrosis. |
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Pedal osteitis is characterized by? |
inflammation of distal phalanx (septic or aseptic) |
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What is the best view for pedal osteitis complex? |
dorso-65-proximal to palmarodistal oblique |
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Radiographic signs of pedal osteitis complex? |
irregular solar margin, increased number of vascular channels, demineralization, +/- circular lucencies |
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Septic pedal osteitis is often secondary to? |
penetrating wound, solar abscess |
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Radiographic signs of septic pedal osteitis? |
focal, poorly defined demineralization of solar margin, gas within hoof wall, reduced bone opacity, wide vascular channels |
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May have _____ secondary to sole abscess/septic pedal osteitis. |
laminitis |
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Keratoma is the most _____ _____ of the distal phalanx. It is ____ _____. |
--most common tumor --not aggressive |
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What are the radiographic signs of keratoma? |
smooth, well-defined bone resorption no new bone production progressive (unlike septic pedal osteitis) |
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Why are keratoma and septic pedal osteitis sometimes difficult to differentiate? |
keratoma can become secondarily infected |
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Rank in order of frequency: septic osteitis, soft tissue sole infection, keratoma |
soft tissue sole infection > septic osteitis > keratoma |
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Swelling within joint capsule is usually _____, while swelling outside joint capsule is usually ______. |
within joint capsule: circumferential outside: asymmetric |
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Differential diagnoses for swelling within joint capsule? (4) |
--increased fluid due to septic arthritis, hemarthrosis, synovitis --synovial proliferation --osteoarthrosis --osteochondrosis |
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Differential diagnoses for swelling outside of joint capsule? |
--diffuse: edema, cellulitis, hemorrhage --localized: hematoma, abscess, contusion |
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What is villonodular synovitis? |
chronic proliferative synovitis proliferation of synovial pad due to repetitive injury |
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Villonodular synovitis causes ______ swelling, _____ of canon bone. Most frequently affects which joint? |
intracapsular swelling, erosion of canon bone fetlock (metacarpophalangeal) |
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Both OCD and OA cause _______ swelling. |
intracapsular |
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Septic arthritis should show what kind of radiographic signs? |
intracapsular swelling WITHOUT bone lesion circumferential swelling well-defined articular surfaces may see gas-fluid interface |
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Intracapsular swelling with bone lesion indicates? |
osteomyelitis |
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Distal tarsal osteoarthrosis (bone spavin) affects which joints? |
distal intertarsal, tarsometatarsal |
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Distal tarsal osteoarthrosis is often _____. |
bilateral |
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What are the radiographic signs of distal tarsal osteoarthrosis? |
periarticular osteophytes joint space narrowing subchondral bone lysis (eburnation) variable ankyloses (jt fusion) loss of corticomedullary definition (sclerosis) small amnt. ST swelling |
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Aseptic physitis causes ______ swelling. |
--extracapsular swelling |
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Aseptic physitis (epiphysitis) is non _____ and non ______ disease likey caused by _____ imbalances. |
non-infectious, non-inflammatory nutritional imbalances |
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Aseptic physitis (epiphysitis) causes ______ defects, and occurs in horses aged ___ - ___ __. |
osteochondral defects 4-8 mo (maybe older) |
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Radiographic signs of aseptic physitis? |
wide physis, irregular margins, usually asymmetrical, sclerosis |
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Aseptic physitis affects one physis or more than one? Treatment? |
--can affect one, or more than one physis --self-limiting disease, correct nutritional imbalances, pain control |
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What is septic physitis? |
osteomyelitis at a physis >> aggressive! |
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Septic physitis is often secondary to _____, and thus is likely to affect ______ _____. It is predisposed to the metaphysis due to ____ ____ ____. |
sepsis, multiple physes low blood flow |
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What are fracture types? What do they look like? |
acute/traumatic--sharp margins chronic/healing--rounded, well-defined margins pathologic--poorly-defined margins |
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What are the fracture descriptors? (6) |
location, sshape, complete/incomplete, displacement, open/closed, articular vs. non-articular |
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Common facture locations in horses? |
digits 3rd metatarsal/metacarpal tibia proximal sesamoid bone distal phalanx |
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Distal phalanx fracture is usually _____, but can be secondary to _____ _____ _____, or _______. |
--traumatic septic pedal osteitis, laminitis |
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Types of distal phalanx fracture? (7) |
1. non-articular fracture of palmar process 2. articular fracture of palmar process 3. articular fracture, midsagittal (midline) 4. articular fracture, extensor process 5. articular fracture, comminuted 6. solar margin fracture (MOST COMMON) 7. foal, palmar process |
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What is the most common type of distal phalanx fracture? It can happen secondary to? |
type 6, solar margin fracture secondary to laminitis |
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Why are distal phalanx fractures difficult to diagnose? |
minimal displacement, limited periosteum, often require multiple views/obliques |
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Proximal sesamoid fracture prognosis depends on? Which fracture has the best prognosis? |
prognosis depends on suspensory ligament branches apical fracture has best prognosis |
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What are the most common types of proximal sesamoid fractures? |
apical (good prognosis) mid-body, basilar (guarded prognosis) |
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Fragments adj. to proximal sesamoid bone might be? |
osteochondral fragment avulsion of palmar annular ligament chip fractures proximal sesamoid bone fracture |
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____ fractures are common in the fetlock and carpus. |
chip fractures |
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____ fractures are common in the carpus, especially _____ carpal bone. |
slab fractures 3rd carpal bone |
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What are slab fractures caused by? |
hyperextension of joint, secondary remodeling, repetitive stress |
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_____ views are especially useful for diagnosis of slab fracture. |
flexed views |
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If fracture is visible on more than one view, what does this indicate? |
more than one fracture! |
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What is nuclear scintigraphy used for? |
assess bone activity |
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Lesions with high bone activity? |
high activity: osteomyelitis and other aggressive bone lesions, acute fractures |
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Lesions with low/moderate bone activity?
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osteoarthrosis, osteochondrosis, chronic/healing fractures |
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Condylar metacarpal fractures are common in ____, _____ thoroughbreds. |
young, racing thoroughbreds |
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All condylar metacarpal/metatarsal fractures have an ______ component. |
articular |
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What is periostitis? What does this cause? |
inflammation of periosteum bone makes bone (but no aggressive lesion) |
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What are bucked shins? What is this disease process? |
increased thickness of dorsal cortex of cannon bone, may see microfractures caused by periostitis |
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What are periostitis splints? Why is this problematic? |
trauma to interosseous ligament causes periostitis >> enthesopathy between bones large amount of bone production can impinge on suspensory ligament. |
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Two disease processes that can impinge suspensory ligament. |
proximal sesamoid bone fractures periostitis splints |
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Radiographic signs of periostitis splints? |
large amount of bone bridging interosseous space between 3rd and 4th metatarsal bones, well-defined margins |
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Sequestration can occur secondarily to? |
bone trauma/fracture complication osteomyelitis ST wounds that extend to bone |
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What is a sequestrum? What is it surrounded by? |
avascular portion of bone, reservoir for infection surrounded by necrotic tissue/pus and periosteal new bone |
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Cuboidal bone hypoplasia predisposes animals to? |
angular limb deformity, jt collapse/fractures |
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What is cuboidal bone hypoplasia? |
failure in appropriate ossification |
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What are the radiographic signs of cuboidal bone hypoplasia? |
small, rounded cuboidal bones increased joint space |
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Tarsal bone collapse occurs in? What are the radiographic signs? Unilateral or bilateral? |
--neonatal foals to young adult horses --excessive flexion/tarsal valgus --central/third tarsal bones wedge shaped/fragments --narrow jt. spaces --intracapsular swelling --usually bilateral |
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Tarsal bone collapse is usually secondary to? What occurs chronicially? |
cuboidal bone hypoplasia, osteomyelitis osteoarthrosis, joint ankylosis |
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Angular limb deformity can be ____ or _____. Which is more common? |
valgus or varus valgus is more common |
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Angular limb deformity can occur secondarily to? |
cuboidal bone hypoplasia asymmetrical growth of epiphysis/metaphysis laxity of ST structures excessive fractures Salter Harris fractures poor conformation nutritional imbalance |
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soft tissue mineralization of hoof cartilages are often ______, but may ______ and cause _____. |
often incidental may fracture and cause lameness |
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Mineralization of hoof cartilages occurs commonly in? |
draft horses |