Musculoskeletal Midterm Flashcards
(181 cards)
1
Q
What are examples of group 2, semicritical, fractures?
A
articular fractures, physeal fxs, joint luxation
2
Q
What time frame should group 2 fractures be treated?
A
2-5 days
3
Q
What type of open fracture is when skin is penetrated from the inside out by sharp bone fragment?
A
type 1
4
Q
What type of open fracture is when skin wound larger than 1 cm?
A
type 2
5
Q
What type of open fracture is when bone is fragmented from high energy trauma?
A
type 3
6
Q
What are the different subclassifications of type 3 open fractures?
A
a - no major reconstruction
b - reconstruction required
c - major arterial injury
7
Q
What type of open fracture requires amputation?
A
type 4
8
Q
What classification scheme is used for physeal fractures?
A
salter-harris scheme type 1 - just physis type 2 - physis and metaphysis type 3 - physis, epiphysis, articular type 4 - physis, meta, epi and articular type 5 - crushing injury
9
Q
Term for fracture with three or more fragments whose lines interconnect.
A
comminuted fx
10
Q
Term for fracture where 3 fragments do not interconnect
A
segmental fx
11
Q
Term for insertion point of a tendon or ligament is fractured and distracted from rest of bone.
A
avulsion fx
12
Q
Term for fracture line perpendicular to the long axis of the bone
A
transverse
13
Q
Term for fracture line is at angle to the long axis of the bone
A
oblique
14
Q
What are the 3 postoperative assessments of fracture repair?
A
alignment
apparatus
apposition - how pieces fit
activity - bone healing
15
Q
Whats the difference between indirect bone healing and direct bone healing?
A
indirect - cartilage precursor
direct - no cartilage
16
Q
What environment does indirect bone healing occur?
A
unstable mechanical environment (strain)
17
Q
Does indirect bone healing increase or decrease fracture gap?
A
increases
18
Q
What are the two types of direct bone healing?
A
contact - simulatneous union and remodeling
gap healing - small gaps fill with fibrous bone, haversian remodeling
19
Q
How does direct bone healing look like on an xray?
A
fracture line increases in density, no bridging or callus
20
Q
When does intramembranous bone healing occur?
A
strain of less than 5%, bridging of comminuted bone fragments occur, smaller callus
21
Q
What does creatinine kinase measure?
A
myonecrosis, peaks at 6-12 hours
22
Q
What does aspartate aminotransferase (AST) measure?
A
cell damage, not specific - skeletal, cardiac muscle, liver, RBC
23
Q
Where is the place to take muscle biopsies for horses for most diseases?
A
semimembranosis (type 2 fibers)
24
Q
What muscle should a biopsy be taken for equine motor neuron disease? (TQ)
A
sacrocaudalis medialis dorsalis (type 1 fibers)
25
What is the most common myopathy in horses?
exertional myopathies
26
What causes HYPP on cellular level?
failure in Na channel in muscle
27
What is the tx for mild HYPP?
mild exercise, feeding grain or corn syrup (insulin)
28
What is the Tx for severe HYPP?
calcium gluconate, IV dextrose, sodium bicarbonate
29
What breeds get recurrent exertional rhabdomyolysis?
thoroughbreds, standardbreds, arabians
30
What is the pathogenesis of RER?
defect in intracellular calcium regulation ->necrotic muscle
31
What are CS of RER?
tying up, pigmenturia, increased CK
32
How is RER treated?
prevent renal damage, correct acid-base, alleviate anxiety and muscle pain
33
What breeds get PSSM?
quarter horses and like-breeds
34
What is the pathology of PSSM?
increased muscle glycogen, enhanced insulin sensitivity
35
How is PSSM diagnosed?
serum CK persistently increased, submaximal exercise challenge test
36
How should PSSM be managed?
increase fat in diet, regular exercise
37
What 3 molecules are responsible for matrix breakdown in osteoarthritis?
aggrecanases, cathepsins, free O radicals
38
What cells produce the mediators that progress osteoarthritis?
chondrocytes, synovial cells, subchondral osteoblasts
39
What are the 3 differential diagnosis for aggressive bone disease?
osteosarcoma, osteomyelitis, blasto
40
Where are common areas of OCD in front limb?
shoulder - caudal humeral head
hock - medial trochlear ridge of talus
elbow - medial humeral condyle
41
What is OCD?
defect in cartilage
42
What are common areas of OCD in hind limb?
stifle - lateral femoral condyle
43
What causes metaphyseal osteopathy/hypertrophic osteodystrophy?
failure of endochondral ossification (young large breed dogs)
44
What is seen with metaphyseal osteopathy on radiographs?
double physis, periosteal proliferation, widened metaphyseal region
45
What will be seen on radiographs with panosteitis?
increased medullary opacity near nutrient foramen
46
What is osteochondromatosis?
benign proliferation of bone and cartilage
47
What age and species is osteochondromatosis seen?
older cats
48
What age and types of dogs do you see femoral head and neck necrosis?
small breed dogs
49
What are the radiographic signs of DJD?
narrowing joint space, subchondral bone lysis, osteophytes
50
What is the signalment for patients with masticatory muscle myosiits?
young to middle aged, german shepherds, retrievers, doberman
51
What antibodies are involved in masticatory muscle myositis?
type 2M fiber antibodies
52
What is the tx for masticatory muscle myositis?
immunosuppressive, azathioprine
53
What is the signalment for patients with extraoculuar myositis?
young large breed dogs
54
What is polymyositis?
diffuse inflammation of skeletal muscle, immune mediated
55
What is breed predilection for polymyositis?
large breed adult dogs - GSD
56
What is the treatment for extraocular myositis?
corticosteroids, will resolve
57
What are the CS of feline idiopathic polymyositis?
acute onset weakness, cervical ventroflexion
58
What is a primary cause of feline hypokalemic myopathy?
renal disease
| also inherited in burmese cats
59
What is the pathogenesis of feline hypokalemic myopathy?
GI loss
translocation from EC to IC (alkalemia, insulin)
urinary loss (renal dz, diuretics)
insufficient intake (anorexia)
60
How is muscular dystrophy inherited?
x-linked recessive trait, variable expression
61
What breeds of dogs and cats get muscular dystrophy?
dogs - golden retriever, GSP, rottie
| cats - DSH, siamese, maine coone
62
What are CS of muscular dystrophy?
weakness, muscle loss in first few weeks of age
63
What breed gets centronuclear myopathy?
labs
64
How is centronuclear myopathy inherited?
autosomal recessive (males and females affected)
65
What 2 inherited myopathies do labs get?
centronuclear myopathy, lab episodic/exercise induced collapse
66
What are CS of exercised induced collapse in labs?
youung adult, paresis, ataxia, recover within 30 mins
67
What dog breed gets fibrotic myopathy?
GSDs
68
What are CS of myotonia?
onset 2-6 months, muscle stiffness, neuro normal
69
What breed mostly gets myotonia?
mini schnauzer
70
What is the hallmark of osteoarthritis?
degeneration of cartilage
71
What are the drugs in the "disease modifying" group of anti arthritic drugs?
hyaluronic acid
PSGAGs - chondroiton sulfate/glucosamine
IRAPs - stem cells
72
What topical NSAID targets cox 2 for osteoarthritis?
diclofinec sodium
73
What is the MOA of corticosteroids?
inhibit phospholipase A
74
What is the MOA of NSAIDs?
inhibit Cox 1 and 2 (want to inhibit cox 2 mostly)
75
What is the best way to deliver corticosteroids in osteoarthritis?
intra-articularly
76
How do corticosteroids produce chondroprotective effects?
inhibit MMPs
77
What is the half life and target of hyaloronic acid?
12-24 hours
| synovial lining
78
What are the MOAs of PSGAGs with osteoarthritis?
inhibit degradation enzymes
inhibit PGE2 synthesis
stimulate matrix synthesis
79
What are the side effects of PSGAGs?
potentiation of infectious arthritis
| hemarthrosis
80
How is IRAP made? (interleukin receptor antagonist)
WBCs of patient and chromium sulfate beads makes them produce antiinflammatory cytokines
81
What drug binds to bone surfaces and poisons osteoclasts as they resorb bone?
bisphosphanates
82
What is the MOA of platelet rich plasma therapy in osteoarthritis?
lysing platelets releases anabolic growth factors, no clinical studies
83
What are stem cells indicated for in osteoarthritis?
intraarticular soft tissue injuries but not cartilage damage
84
What are CS of rickettsial disease involvment with arthritis?
polyarthritis, lymphadenopathy, thrombocytopenia
85
What type of infectious arthritis spreads to other joints locally?
lyme arthritis
86
What type of arthritis results from systemic inflammation?
reactive polyarthritis (immune complexes)
87
What is the most common form of polyarthritis in dogs?
idiopathic polyarthritis (immune mediated)
88
WHat joints are more severely affected in idiopathic polyarthritis?
distal joints (hock, carpus)
89
What are CS of shar pei fever?
episodes of fever, swelling around hock, young dogs
90
What may be seen with joint tap in hock fever in sharpeis?
amyloidosis
91
What disease results in subcutaneous abscesses and causes polyarthritis in cats?
L form-associated arthritis
92
What are the "erosive" forms of joint disease in SA?
L-form arthritis, greyhound arthritis, rheumatoid arthritis, feline chronic progressive polyarthritis
93
What happens in the joints with rheumatoid arthritis?
is like idiopathic polyarthritis but joints destroyed over a few weeks
94
What type of reduction is indicated in articular fractures?
open reduction
95
What type of reduction is indicated in comminuted nonreducible diaphyseal fractures of long bones?
```
open reduction or
closed reduction (external fixator)
```
96
What type of reduction is indicated in greenstick or nondisplaced fractures of long bones below elbow and stifle?
closed reduction
97
Term for ability of the material to induce migration and differentiation of mesenchymal stem cells into osteoblasts via presence of transforming growth factor beta superfamily.
osteoinduction
98
Term for the ability of cells to survive transplantation and serve as source of osteoblasts
osteogenesis
99
Term for ability of the material to provide a scaffold for host bone invasion
osteoconduction
100
Term for the surface bonding between graft and host bone
osteointegration
101
Where can cancellous bone autografts be harvested on a patient?
proximal humerus, proximal tibia, ilial wing (metaphysis)
102
Where can cortical bone autografts be harvested on a patient?
ribs, ilial wing, distal ulna and fibula
103
What type of lameness may be indicated if a horse is "on a right line"?
suspect right forelimb lamness
104
What type of lameness is indicated if the horse is "on the right shaft"?
left hindlimb lamness
105
What are the factors that increase stiffness in an ESF?
```
increasing pin diameter (up to 25% of bone diameter
pin number (2-4)
pin location closer to fracture
clamp 1 cm from skin
connecting bar size and number
```
106
What are the 4 different types of ESFs?
Type 1a - unilateral, uniplanar
Type 1b - unilateral, biplanar
Type 2 - bilateral, uniplanar
Type 3 - bilateral, biplanar
107
Is loop cerclage wire or twisted cerclage better for tension?
loop
108
How does cerclage wire affect blood supply to long bone?
no effect if placed correctly, if loose, will disrupt periosteal blood supply
109
WHat is the advantage to IM pins?
very resistant to bending forces
110
What is the disadvantage to IM pins?
do not counteract rotational forces (smooth pin)
111
What is the most commonly used IM pin?
steinmann pins, trocar point
112
How should IM pins be placed in the tibia?
always normograde
113
What bone should IM pins not be placed?
radius
114
What fractures are good for interlocking nail IM pins?
comminuted diaphyseal fractures
115
What is the maximum size of an ESF pin?
no larger than 25% of bone
116
What is the maximum size of a bone screw?
no larger than 40% of bone
117
What are the differences between cortical and cancellous screws?
cortical - more threads per inch
| cancellous - larger outer diameter
118
What is the advantage of using locking head screws?
head of screw has threads, locks into plate to provide stability
119
How are positional screws placed different than compression screws?
compression screw must be perpendicular to fracture line
cis cortex must have gliding hole
trans cortex must have threaded hole
120
What are the three types of bone plates?
compression
neutralization
bridging
121
What type of bone plate is best for fracture lines that are transverse or short oblique no greater than 45 degrees?
compression plate
122
What type of bone plate is best for reducible comminuted fractures and oblique fractures greater than 45 degrees?
neutralization plate
123
What type of bone plate is best for fragmented diaphyseal fractures where reduction is not possible?
bridging plate
124
What are characteristics of a dynamic compression plate?
oblong holes
125
Where must screws be placed on a DCP to get compression? neutralization?
neutralization - centrally
| eccentrically - compression (loaded)
126
What are characteristics of bridging plate?
no holes in the middle, stronger
127
What is a LC-DCP plate?
bottom surface of plate is scalloped to decrease periosteal blood supply disruption
can compress in either direction
128
Term for horse foot is thrown outward in flight but lands inside the normal track.
paddling
129
Term for horse foot swings inward in flight but often lands outside normal track. Can result in interference.
winging
130
Term for horse feet are placed directly in front of one another, associated with base narrow/toe out conformation.
plaiting
131
Term for horse food striking a limb with the opposite limb.
interfering
132
Term for horse hitting the sole of the forefoot with toe of ipsilateral hindfoot
forging
133
Term for hitting the heels of the forefoot with ipsilateral hindfoot
overreaching
134
How long should forelimb flexion tests last? Which one is the most specific?
distal limb - 30 s
carpus - 60 s, most specific
shoulder - 60 s
Elbow - 60 s
135
What does a wedge test do?
exacerbates problems in the foot
136
What is blocked by palmar/planter digital nerve block? (medial and lateral PD nerves)
blocks heel, caudal 1/3 of foot
137
What does a PD block with a ring block desensitize?
whole foot
138
What does an abaxial sesamoid block desensitize?
foot and pastern
139
What is desensitized by the low palmar/planter block?
fetlock
140
What are the 3 main proposed hypothesis of pathogenesis of laminitis?
1. blood flow alterations --> cell death
2. BM breakdown by endogenous enzymes stimulated by toxin
3. systemic inflammatory response leading to inflammation in lamellae
141
What phase of laminitis is the period between first signs of lamness to rotation or sinking?
acute
142
What phase of laminitis is mild lamness without mechanical failure?
subacute
143
What are the different types of the chronic stage of laminitis?
early chronic - first several months
chronic active - recurrence after improvement
chronic stable - stable coffin bone with improvement in hoof
144
What drug can be used as a free radical scavenger in laminitis cases?
dimethyl sulfoxide
145
What is the duration of analgesics for lameness diagnostics?
lidocaine - 1.5-3 hrs
mepivicaine - 2-3 hrs (most used, less irritating)
bupivicaine - 3-6 hrs
146
What are the landmarks for palmar or plantar digital nerve block?
distal pastern just proximal to collateral cartilages
147
What nerves are blocked by abaxial sesamoid nerve block?
medial and lateral palmar/planter nerves
148
What is blocked by the abaxial sesamoid nerve block?
entire digit and pastern +/- partial fetlock
149
What nerves are blocked by low palmar/plantar block in a horse?
medial and lateral palmer nerves, and medial and lateral palmar metacarpal nerves
150
What structures are blocked by low palmar block?
fetlock, pastern, digit
151
What nerves are blocked by high palmar block?
same nerves as low palmar block --> medial and lateral plamer nerves, and medial and lateral palmar metacarpal nerves
152
What nerves does the high palmar block?
entire metacarpus
153
What does the median, ulnar, and musculocutaneous nerve block in a horse?
mid to distal antebrachium and carpus
154
What structures does the peroneal and tibial nerve block in a horse?
distal crus, tarsus, and metatarsus
155
What nerve block blocks the fetlock joint?
metacarpophalangeal/metatarsophalangeal joint block
156
What 2 joints are blocked by the tibiotarsal joint block?
tibiotarsal and proximal intertarsal joints
157
What radiographic technique is better for determining laxity in hip dysplasia patients?
PennHIP
158
At what age is pubic symphysiodesis for hip dysplasia done?
12-20 weeks
159
What surgical procedure can be performed for hip dysplasia if patients are too old for pubic symphysiodesis?
triple pelvic osteotomy
160
What types of puncture wounds of the sole of the horse are most severe?
around the frog - emergency if involves synovial structure
161
Term for deviation of limb medially.
varus
162
What is the most common angular limb deformity in foals?
carpus valgus
163
What breeds are susceptible to periarticular laxity angular deformities?
"windswept" standardbreds and drafts
164
Which angular limb deformities is restricted exercise indicated?
DOCBs - delayed ossification of cuboidal bones
165
What surgical technique is used for growth acceleration in angular limb deformities?
periosteal elevation - releave tension on concave aspect
166
What surgical technique is used for growth retardation in angular limb deformities?
transphyseal bridging
167
What is the time frame for periosteal elevation/stripping correction in the fetlock?
less than 4 weeks
168
What is the time frame for periosteal stripping/elevation correction in the carpus?
less than 6 months
169
What type of cranial cruciate ligament rupture results from acute trauma?
failure of tibial attachment site
170
What is the most commonly performed surgery for cranial cruciate rupture?
lateral fabellar-tibial suture (extracapsular)
171
What is the difference between osteotomies and extracapsular techniques in repairing a cranial cruciate rupture?
osteotomies change biomechanics of joint (affects cranial tibial thrust)
172
What is an alternative to TPLO for immature patients to avoid cutting into physis?
tibial wedge ostectomy
173
When do acquired flexural limb deformities most commonly appear in horses?
4 weeks to 4 months of age or as yearlings
174
What nutritional factors are involved in acquired flexural deformities in horses?
excessive intake, abrupt change, mineral imbalance
175
What drug can be given IV to younger foals as part of conservative treatment of flexural limb deformities?
oxytetracycline - dramatic response but doesnt last
176
What is the surgical treatment for an angular limb deformity in the DIP(coffin) joint?
inferior check ligament desmotomy, DDFT tenotomy
177
Where are DDFT tenotomy usually performed?
level of pastern or at mid-metacarpus (more proximal is easier but can get blemish)
178
What is the sx tx for flexural limb deformities at the MCP joint?
superior check ligament desmotomy +/- ICL desmotomy
179
What is the sx tx for flexural limb deformities at the carpal joint?
ulnaris lateralis, flexor carpi ulnaris tenotomy
180
What should be avoided in flexor tendon laxity in foals?
no splinting or bandaging!!!!!
181
What are CS of ruptured common digital extensor tendon in foals?
swelling in tendon sheath at dorsolateral carpus, buckled knees
