Equine Orthopedics Flashcards Preview

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Flashcards in Equine Orthopedics Deck (172)
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1
Q

what background information should be gained when performing a lameness work up on a horse?

A
signalment
use
duration of ownership
recent management
previous medical problems
2
Q

why is duration of ownership of horses valuable information?

A

shows owner awareness of history

3
Q

what should be asked about horses recent management before a lameness workup?

A

work/exercise
feeding
shoeing ( barefoot / frequency of trims)
housing

4
Q

why is useful to know about the use of a horse when diagnosing lameness?

A

possible differential diagnosis

owner expectations for recovery

5
Q

what specific history is needed for a lameness work up?

A

limb or limbs affected
timing and nature of onset of signs
associated events or incidents
details of any areas of swelling, heat or pain
progression of signs since onset
treatments or management employed to date
current state of problem

6
Q

what are the aims of the initial lameness workup?

A
decide if horse is lame or sound
identify limb(s) affected
score severity of lameness
try to identify source / cause
implement treatment plan
7
Q

what are the steps involved in an initial lameness workup?

A
general physical exam
focused exam of MSK system
gait evaluation (walk, trot and lunge)
flexion tests
further exam of affected limb
8
Q

what may be involved in a further lameness workup, following initial?

A

nerve or joint blocks

diagnostic imaging

9
Q

what is involved in the general physical exam in a lameness workup?

A
general clinical exam (TPR)
general body condition
conformation of body, limbs and feet
posture and weight bearing on the limbs
skeletal and soft tissue symmetry
localised swellings/thickening (from a distance)
10
Q

what may posture and weight bearing on limbs tell you about lameness?

A

whether the horse is trying to reduce pain

11
Q

how should skeletal and soft tissue symmetry be assessed?

A

stood square on a flat surface

12
Q

what is involved in a detailed physical exam of the limbs?

A

feeling limbs, joints and soft tissue
inspection
palpation
manipulation

13
Q

what are hoof testers used for?

A

applied to hooves in various places to put pressure on and assess response

14
Q

what is done after the physical exam during a lameness workup?

A

gait evaluation

15
Q

what do we need to establish from gait evaluation in a lameness workup?

A
is there gait abnormality
is the abnormality due to lameness or something else e.g. neurological
what degree of lameness is there
which limbs are affected
what exacerbates lameness
16
Q

where should gait evaluation be performed?

A

different surfaces - soft and hard if facilities allow

17
Q

what should the gait evaluation start with?

A

walk

18
Q

why should all gait evaluation start with walk?

A

if obviously lame at walk should not trot due to further injury risk

19
Q

what is involved in gait evaluation?

A

walk
trot in a straight line
lunging on soft and hard surfaces

20
Q

what PPE is needed for trotting up?

A
hat
gloves
steel toe capped boots
overalls 
gloves
21
Q

where should horses be trotted up?

A

safe area
enclosed / contained
flat surface
care with surface if raining

22
Q

when may trotting / walking up not be appropriate?

A

if horses is severely lame

23
Q

what must be considered about the horse before trotting up?

A

temperament

restraint

24
Q

how may horses be restrained for trotting up?

A

headcollar

bridle if needed

25
Q

when should forelimb lameness be assessed?

A

a the horse is walking / trotting towards you

26
Q

how is forelimb lameness identified?

A

head nod

head lifts UP when lame leg hits the ground

27
Q

when is hindlimb lameness assessed?

A

as the horse is walking / trotting away from you

28
Q

is forelimb or hindlimb lameness easier to identify?

A

forelimb

29
Q

how is hindlimb lameness identified?

A

hip of the lame limb will rise and fall through a greater range of motion than the sound side

30
Q

how will the hindquarters as a whole behave if a horse is lame?

A

pushed up by sound limb and sink during stance phase of lame limb

31
Q

what else can be assessed during gait evaluation?

A

relative lengths of phases of stride
arc of foot flight
path of foot flight (medial or lateral)
foot placement

32
Q

what is a lameness locator?

A

technology used to aid lameness evaluation

sensors are worn by the horse and computer program helps to identify asymmetry in the stride

33
Q

where may lameness locator sensors be placed?

A

poll, hoof and rump usually

34
Q

what is a lameness locator useful for?

A

helping clinician to identify and quantify subtle lameness

not a replacement for visual evaluation

35
Q

what are the 2 main systems used to grade lameness?

A

out of 5

out of 10

36
Q

what system of grading lameness is the most common?

A

out of 10

37
Q

when reassessing and grading lameness who should assess?

A

clinician who assigned initial grade as there are individual differences

38
Q

what are the uses of flexion (provocative) tests?

A

demonstrate occult lameness in a ‘sound’ horse
exacerbate mild lameness
aid localisation of lameness source

39
Q

what is assessed in flexion tests?

A

response of the limb to flexion

40
Q

what happens during a flexion test?

A

limb held in flexion for ~1 minute

horse trotted away as soon as the limb is released

41
Q

how should the horse be standing for a flexion test?

A

ready to trot away (straight line, facing away)

42
Q

what is assessed during a flexion test?

A

does lameness continue longer than would be expected after flexion (horse allowed a few lame strides)

43
Q

what joints should be flexed during flexion tests?

A

attempt to only flex those you are testing (easier said than done!)

44
Q

what are the limitations of flexion tests?

A

lack of specificity to site
inconsistency
lack of clear criteria for positive - what is the cut of of allowed lame strides
false positives and negatives

45
Q

why is lunging of benefit in a lameness work up?

A

lameness often exacerbated on a circle

46
Q

when lunging when is lameness particularly obvious?

A

when lame leg is on the inside due to increased weight bearing

47
Q

what surfaces can lunging be performed on?

A

hard and soft ground

48
Q

why is hard ground lunging useful?

A

usually exacerbates lameness more (although not always)

49
Q

what PPE is needed for lunging?

A

hat
steel toe capped boots
gloves
overalls

50
Q

what equipment is needed for lunging?

A

lunge line
lunge whip
bridle / cavesson
boots

51
Q

where is lunging performed?

A

soft lunge - school or pen

hard lunge - hospitals will usually have designated flat area that is secure and has appropriate surface

52
Q

what questions should be asked before lunging?

A

does the horse lunge well

53
Q

when are further lameness workups needed?

A

established that horse is lame, how lame and what leg

54
Q

what is involved in a further lameness work up?

A

physical exam of specific limb(s)
diagnostic analgesia
diagnostic imaging

55
Q

what is involved in nerve ant joint blocks?

A

perineural, intrasynovial or local infiltration of LA into areas of the limb to progressively identify area of source of lameness

56
Q

what LA is used for nerve and joint blocks?

A

Intra-epicaine (mepivicaine)

57
Q

where should nerve blocks be started?

A

distally and work up

58
Q

how should the area be prepped for nerve blocks?

A

clean area with chlorhex and spirit

can be clipped

59
Q

how are nerve blocks usually performed?

A

unsedated as movement is assessed

safety is crucial

60
Q

how should nerve blocks be performed?

A

LA injected

leave for 10 mins and then trot up to check for improvement

61
Q

what does improvement of lameness after a nerve block indicate?

A

problem is located between nerve blocked areas

62
Q

what are the 3 nerve blocks used in lameness workup?

A

palmar/plantar digital
abaxial sesamoid
low 4 point

63
Q

what equipment is needed for nerve blocks?

A

23-25G, 5/8” needles

2ml syringes

64
Q

identify the nerve block

A

medial and lateral palmar/planter digital

65
Q

identify the nerve block

A
abaxial sesamoid (medial and lateral)
location of digital pulse
66
Q

identify the nerve block

A

low 4 point (medial and lateral - 4 needles)

67
Q

where are joint blocks performed?

A

blocking into a joint (intrasynovial)

68
Q

what is key when administering joint blocks?

A

sterility

69
Q

how should skin be prepped for joint blocks?

A

sterile skin prep - chlorhexadine and spirit

70
Q

when are the results of joint blocks evaluated?

A

10 mins and then later to see if there has been LA infiltration

71
Q

when is lameness diagnostic imaging performed?

A

once an area of source of lameness is identified

72
Q

why do we need to narrow down source of lameness before diagnostic imaging is performed?

A

to limit imaging and so radiation exposure

73
Q

what can be interpreted using diagnostic imaging?

A

significance of any finding

74
Q

what does the choice of diagnostic imaging modality depend on?

A

suspected source of lameness

75
Q

what PPE is needed for radiographs?

A

lead gowns

thyroid protectors

76
Q

how are horses usually restrained for imaging?

A

sedation to keep them still

77
Q

what are radiographs useful for?

A

identifying bony change

78
Q

what is ultrasound used for in horses?

A

distinguishing tendon/ligament injuries from peritendinous swelling
defines the tendon/ligament that is injured
evaluates type and degree of damage
monitors healing

79
Q

how should horses be prepped for ultrasound?

A

clip area if required
clean to remove dirt
apply US gel

80
Q

how are horses restrained for US?

A

may need sedation to stay still

81
Q

what are you looking for during diagnostic ultrasound in a lameness workup?

A

Increase in tendon/ligament size
Change in internal architecture
Indistinct Margination
Peritendinous fluid in tendon sheaths

82
Q

what changes in internal architecture of tendons may be seen on ultrasound?

A

hypoechoic core lesions
heterogenous pattern -
loss of longitudinal fibre alignment

83
Q

what are hypoechoic core lesions?

A

black hole in centre of tendon

84
Q

what is diagnostic arthroscopy?

A

direct visualisation of joint cavities with a scope

85
Q

what can be viewed during arthroscopy?

A

Articular cartilage
Synovial membrane
Intra-articular Ligaments
Menisci

86
Q

what are the limitations of diagnostic arthroscopy?

A

Requirement for general anaesthesia

Inability to examine most joints in their entirety

87
Q

what is the benefit of MRI and CT?

A

Cross sectional imaging of complex anatomical structures

88
Q

what is the benefit of MRI for lameness investigation?

A

simultaneous demonstration of bone and soft tissue structures
see within hoof

89
Q

what can be evaluated by MRI?

A

tendons/ligaments and other soft tissues

90
Q

how does nuclear scintigraphy work?

A
radioactive isotope is linked to marker which binds to metabolically active bone
injected IV
taken up by bone
emits radiation
gamma camera detects radiation
91
Q

what radioisotope is used in nuclear scintigraphy?

A

technetium 99m

92
Q

what is the marker used in nuclear scintigraphy?

A

methylene diphosphonate

93
Q

how long does the radioisotope emit radiation for?

A

half life is 6 hours

94
Q

what lesions can be detected by nuclear scintigraphy?

A

Stress fractures
Arthropathies
Enthesiopathies - connective tissue

95
Q

what should happen to the horse prior to injection of radioisotope if safe?

A

lunged or exercised

96
Q

why should as horse be lunged or exercised prior to nuclear scintigraphy if safe?

A

increases uptake

97
Q

what must be placed before nuclear scintigraphy is performed?

A

IV catheter

98
Q

what is the disadvantage of nuclear scintigraphy?

A

horse will remain radioactive for a period of time after injection

99
Q

how should the horse be managed after nuclear scintigraphy scan?

A

Urine will need to be collected during the image acquisition

Must be kept in isolation until no longer radioactive - no handling, no mucking out etc.

100
Q

what is synovial sepsis?

A

bacterial cntamination of synovial structure

101
Q

where dies synovial sepsis often occur?

A

wounds in adults that penetrate joints

102
Q

what does synovial sepsis cause if not treated?

A

septic arthritis and chronic lameness

103
Q

how should suspected synovial sepsis be investigated?

A

Synoviocentesis and analysis of synovial fluid
May inject sterile saline into the joint and check for egress
Contrast radiography

104
Q

what is vital when performing arthrocentesis?

A

sterility

105
Q

how should the patient be prepped for arthrocentesis?

A

Sterile prep of the athrocentesis/synoviocentesis site
Chlorhexidine 5 min minimum scrub
Wipe with surgical spirit

106
Q

what needle is required for arthrocentiesis?

A

depends on joint

107
Q

what restraint is usually used for arthrocentesis?

A

sedation

108
Q

what is the role of the nurse in arthrocentesis?

A

Prep the site (vets may choose to prep this themselves)
Non-sterile assistant during arthrocentesis
Have equipment and spares ready (e.g. needles, syringes, sterile gloves, tubes/pots for collection)
Monitoring for lameness/deterioration in lameness in the post 48 hours

109
Q

what is shown by injection of sterile saline into the joint and there being egress from wound?

A

communication between joint and wound so likely infection

110
Q

why must the patient be monitored closely for 48 hours following arthrocentesis?

A

procedure can cause synovial sepsis

111
Q

what is analysed from arthrocentesis?

A

cytology
protein conc
lactate
serum amyloid A (SAA) blood sample

112
Q

what is cytology of arthrocentesis sample checking for?

A

TNCC and neutrophil %

113
Q

what tubes are needed for arthrocentesis?

A

EDTA or cytospin for cytology

plain tube - culture and TP

114
Q

define laminitis

A

inflammation of the interdigitating laminae/lamellae in the hoof

115
Q

what does laminitis cause?

A

dermal/epidermal separation and reduction in structural integrity of the hoof

116
Q

is laminitis painful?

A

yes - very

117
Q

what can laminitis lead to?

A

structural changes/failure in the foot

118
Q

what structural changes / failure in the foot can be caused by laminitis?

A

rotation of P3

sinking of P3

119
Q

what are the 4 main phases of laminitis?

A

developmental
acute
subacute
chronic

120
Q

when does the developmental phase of laminitis occur?

A

between trigger and clinical signs

121
Q

what happens during the acute phase of laminitis?

A

onset of clinical signs

122
Q

how long does the acute phase of laminitis usually last?

A

72 hours

123
Q

what can happen after the acute phase of laminitis?

A

may become chronic or subacute

124
Q

when does subacute laminitis occur?

A

from 72 hours after onset of acute signs

125
Q

how long does subacute laminitis take to repair?

A

2-3 months

126
Q

what happens in chronic laminitis?

A

structural failure of the structures of the hoof

127
Q

what are the clinical signs of laminitis?

A
stilted, pottery gait
increased, bounding digital pulses
leaning back on heels
recumbancy
worse on hard ground
struggle to turn
reluctance to pick up feet
128
Q

what are the main causes of laminitis?

A
endocrinopathies
excessive carbohydrates
excessive weightbearing
endotoxaemia / SIRS
corticosteriods
129
Q

is the absolute pathogenesis of laminitis known?

A

not precisely understood

potentially multiple mechamisms

130
Q

how may excessive carbohydrates cause laminitis?

A

grain overload

pasture (linked to PPID)

131
Q

what underlying endocrinopathies can cause laminitis?

A

equine metabolic syndrome (EMS)

pituitary pars intermedia dysfunction (PPID)

132
Q

what is the likely pathophysiology of the link between endocrinopathies and laminitis?

A

disregulation of insulin leading to hyperinsulinaemia and insulin toxicity

133
Q

what are the vast majority of the cases of laminitis caused by?

A

endocrinopathies (although depends on population)

134
Q

what are the majority of pasture related laminitis cases caused by?

A

endocrinopathies - sugars in pasture cause insulin spike

135
Q

what are the causes of laminitis seen most commonly in the hospital setting?

A

supportive limb laminitis

endotoxaemia

136
Q

how is supporting limb laminitis caused?

A

excessive weightbearing

especially if on one limb only

137
Q

what conditions often lead to supporting limb laminitis?

A

fractures

cellulitis

138
Q

how can endotoxaemia be caused and so lead to laminitis?

A

secondary colic
colitis
retained fetal membranes

139
Q

what are the risk factors for laminitis?

A
history of laminitis
obesity
endocrinopathies (PPID, EMS)
age (PPID)
insulin resistance
leptin/adiponectin (EMS)
season 
heavy horses
native horses
excessive weightbearing
excessive carbohydrates
risk of endotoxaemia
140
Q

when can laminitis be prevented?

A

developmental phase before clinical signs

141
Q

what patients should have preventative laminitis management?

A

those at risk - endotoxic, RFM, supporting limb

142
Q

how is developmental laminitis managed?

A

cold therapy with ice boots to reduce perfusion
NSAIDS reduce inflammation
support for feet

143
Q

how can feet be supported to manage developmental laminitis?

A

frog supports

deep shavings bed

144
Q

what is the role of frog supports in managing developmental laminitis?

A

lift heel to reduce pressure from DDF on P3

145
Q

how should horses with developmental laminitis and endocrinopathies be treated?

A

treat underlying endocrinopathy

discussion of prevention and long term management (e.g. diet and weight loss)

146
Q

how should acute laminitis patients be managed?

A

strict and complete box rest / restricted movement
deep shavings bedd
frog supports or Styrofoam pads
NSAIDS - analgesia and reduce inflammation
ACP to increase perfusion (vasodilation)
treat underlying cause
address diet

147
Q

how should the diet of an acute laminitis patient be addressed if they have endocrinopathies?

A

reduce carbohydrates (e.g. steam or soak) but not dramatically

148
Q

why is it important to reduce carbohydrates in a horses diet gently if needed?

A

reduce risk of colic and hyperlipaemia

149
Q

what should be done to treat acute laminitis once the patient is more comfortable?

A

farriery

150
Q

how should subacute laminitis be treated?

A

gradually withdraw treatment as long as improving
keep on strict box rest
radiology and farriery to alter foot balance

151
Q

how can radiography and farriery be used to treat subacute laminitis?

A

shorten toe over time
use radiographs to calculate shortening needed
remedial shoeing

152
Q

what remedial shoeing may be used for laminitis patients?

A

heart bar shoes
silicone
glue on shoes

153
Q

what are the main radiographic views needed for laminitis assessment?

A

lateromedial

dorsopalmar/planter

154
Q

what is the aim of radiographs for the laminitis patient?

A

measure rotation and sinking of P3

look for prognostic indicators

155
Q

what prognostic indicators may be seen on a hoof radiograph of a laminitis patient?

A

separation of laminae e.g. gas shadowing

156
Q

why may radiography be difficult in a very painful laminitic?

A

need to have feet picked up and stand on blocks

157
Q

what must be placed on the dorsal hoof wall to ensure measurements can be taken from radiographs?

A

metal marker from coronary band down the front of the hoof wall

158
Q

what is the angle of rotation?

A

angle between dorsal hoof wall and dorsal boarder of P3 - should be no intersecting angle as line should be paralledl

159
Q

how can laminitis be managed / prevented?

A

control risk factors
treat underlying endocrinopathy (if present)
weight loss - promote ideal endocrinopathy
diet
restrict graing

160
Q

what can be beneficial to reduce insulin sensitivity?

A

exercise

161
Q

how should the diet of a horse prone to laminitis be manged?

A

restrict carbohydrates

soak hay and give balancer to replace nutrients

162
Q

how should grazing for the laminitis prone horse be restricted?

A

not by time
strip grazing
grazing muzzle

163
Q

which of the laminitis risk factors is it possible to directly manage?

A
obesity
endocrinopathy
insulin resistance
diet
excessive weightbearing
endotoxaemia
164
Q

what is box rest?

A

stabling 24/7 in a confined space with no exercise or turnout

165
Q

what changes for the horse when it is put on box rest?

A
limited exercise
change in routine
change in diet (required)
no turnout
may be unused to stabling
boredom
reduction in time eatng
166
Q

how may the horses behaviour be affected by box rest?

A

separation from friends
boredom
lack of exercise leading to excessive energy

167
Q

what are the main GI considerations for a horse on box rest?

A

management changes can lead to colic
reduced exercise can reduce gut motility - impaction colic
sudden diet changes can lead to colic
diet will have to be adjusted for new energy requirements
ulcers due to reduced eating time

168
Q

how can the risk of ulcers due to reduced eating time on box rest be reduced?

A

omeprazole
small holed haynets
food toys - consider illness being treated!

169
Q

what are the main behaviour considerations for a horse on box rest?

A

may develop stereotypies if bored / frustrated
unused to stabling so may be stressed
separation from stable mates - mirror?
increased energy leading to poor behaviour in stable and trying to escape - may barge / spook when allowed out

170
Q

how should the patient on box rest be nursed?

A
monitor faecal output
monitor for colic
monitor appetite and signs of stress
offer mirrors or a form of company
watch out for behaviour changes - more keen to escape and more difficult to handle
171
Q

how should patients come off box rest?

A

gradual changes in management back to normal
gradual change back to normal diet
gradual return to turn out
slow reintroduction to work

172
Q

what should you be wary of when a horse is first turned out after box rest?

A

gradual return to turn out
sedation or small field for first time out
watch behaviour

Decks in X Clinical Veterinary Nursing Theory Class (70):