Orthopaedics Flashcards
1
Q
what cells are found in bone?
A
osteoclasts
osteocytes
osteoclasts
2
Q
what is the bone matrix made of?
A
collagen
hydroxyapatite crystals
3
Q
what is the function of bone?
A
skeletal support protection haematopoesis regulation of mineral homeostasis fat storage
4
Q
what is the precursor to bone in utero?
A
cartilage
5
Q
what are the two types of bone?
A
cortical cancellous bone (trabecular bone)
6
Q
where is cancellous bone found?
A
metaphysis
flat bone
cuboidal bone
7
Q
what is the function of cancellous bone?
A
dissipation of load
8
Q
what process increased bone length?
A
endochondral ossification
9
Q
what process is responsible for cuboidal bone development?
A
endochondral ossification
10
Q
what is appositional growth?
A
increases length
11
Q
what is longitudinal growth?
A
increase longitudinally
12
Q
what is modelling?
A
alteration in the shape of the bone
13
Q
what happens to the trabecular bone when load/exercise is increased?
A
increased thickness
increased bridging between trabeculae
(modelling by microfractures)
14
Q
what is bone remodelling?
A
replacement of damaged bone
15
Q
define anisotropic
A
describes how a substance responds to load depending on the speed it is loaded
16
Q
what determines the mechanical properties of bone?
A
size/shape
magnitude of load
direction of load
rate of loading
17
Q
what are the two responses to load?
A
elastic deformation
plastic deformation
18
Q
what is elastic deformation?
A
with loading/unloading the bone deforms and returns to its original shape
19
Q
what is plastic deformation?
A
with loading/unloading the bone deforms but doesn’t return to its original shape (microcracks, incomplete fractures…)
20
Q
what does plastic deformation trigger?
A
bone remodelling
21
Q
what is the consequences of repeated plastic deformation?
A
weakening of normal bone
complete failure of bone
22
Q
what are three metabolic bone diseases?
A
parathyroid hormone abnormality
vitamin D deficiency
paraneoplastic
23
Q
what is developmental orthopaedic disease?
A
group of diseases of multifactorial aetiology resulting in musculoskeletal problems
24
Q
where does endochondral ossification occur?
A
metaphysical growth plate
articular-epiphyseal cartilage complex
25
what are the stages seen at the growth plate?
```
resting cartilage
proliferative cartilage
hypertrophic cartilage
calcifying cartilage
secondary spongiosa
```
26
what is required for cartilage to mineralise?
blood supply
27
what ways can endochondral ossification malfunction at the physical growth plate?
abnormal deposition of matrix
abnormal mineralisation
poor conversion of bone
retention of cartilage
28
what is the results of endochondral ossification malfunction at the physical growth plate?
slow growth
| uneven growth
29
what ways can endochondral ossification malfunction at the articular-epiphyseal cartilage complex?
abnormal deposition of matrix
abnormal mineralisation
retention of cartilage
30
what is the results of endochondral ossification malfunction at the articular-epiphyseal cartilage complex?
slow growth
uneven growth
cartilage flaps
31
what is chondrodysplasia?
dwarfism
32
what is osteochondrosis?
general term to describe abnormalities of cartilage within a joint
33
what is osteochondritis?
inflammation of the cartilage within a joint
34
what is osteochondrosis/osterochondritis dissecans?
the formation of cartilaginous or osteochondral flaps and undulations
35
what is OCD?
osteochondritis dissecans
36
when can abnormalities occur to cause osteochondritis dissecans?
disruption of blood supply
abnormal chondrocyte maturation
defective matrix production
persistence of hypertrophic chondrocytes
37
what does OCD lead to?
thickened retained hypertrophic cartilage
| disruption to the subchondral bone plate
38
how can disrupted blood supply lead to OCD?
affects the mineralisation of the bone altering the biochemical and biomechanical properties of bone
39
what is the first clinical sign of OCD?
effusions (swelling of the joint)
40
what are some risk factors for OCD?
rapid growth (cattle/pigs)
genetics
nutrition
trauma
41
what nutritional influence effect OCD?
excess energy/protein
| imbalances in calcium and phosphate
42
what can untreated OCD result in?
osteoarthritis
43
how does OCD appear on radiographs?
```
irregular subchondral bone
osseous densities (fragments in joint)
```
44
what are some developmental orthopaedic diseases of horses?
osteochondrosis
physitis
angular limb deformities
flexural deformities
45
what are some developmental orthopaedic diseases of dogs?
osteochondrosis
hypertrophic osteodystrophy
legg calve perthes
hip dysplasia
46
what are some developmental orthopaedic diseases of cows?
osteochondrosis
| flexural deformities
47
what are some developmental orthopaedic diseases of pigs?
osteochondrosis
48
what can cause subchondral cyst like lesions?
abnormal endochondral ossification (collapse)
| trauma of articular cartilage and SC bone
49
what is physitis?
enlargement of the physis through inflammation and disrupted endochondral ossification
50
what are the clinical signs of physics?
lameness
| stiff gait
51
what aged dogs does hypertrophic osteodystrophy occur in?
2-8 month old (large breeds)
52
what is the pathogenesis of hypertrophic osteodystrophy?
necrosis of the capillary loops of the cartilage of the metaphysical physis leads to a cuff of metaplastic cartilage
53
what are the clinical signs of hypertrophic osteodystrophy?
lameness, pain
fever
(bilateral and symmetrical)
54
what radiographic abnormalities are seen in dogs with hypertrophic osteodystrophy?
abnormal bone on diaphysial side of physis
decreased radio density parallel to physis
irregular widening of physis
55
what is done to treat hypertrophic osteodystrophy?
self limiting
56
what type of bones is effected by hypertrophic osteodystrophy?
long
57
what age dogs are effected by panosteitis?
5-18 months old (large breeds)
58
what type of dogs are most effected by panosteitis?
rapidly growing large breeds (males)
59
what is the pathogenesis of panosteitis?
increased osteoblastic and fibroblastic activity leads to fibrosis of bone tissue
60
what are the clinical signs of panosteitis?
acute shifting lameness and pain
61
what radiographic abnormalities are seen of dogs with panosteitis?
increased opacity of medullary cavity
indistinct trabecular pattern
increased endosteal opacity
62
what is done to treat panosteitis?
self limiting
63
what aged dog is legg calve perthes disease seen in?
4-11 months (toy breeds)
64
what is the pathogenesis of legg calve perthes disease?
avascular necrosis of the femoral head leads to collapse of the of the articular surface
65
what are the clinical signs of legg calve perthes disease?
acute onset lameness
66
what are the radiographic abnormalities seen with legg calve perthes disease?
osteolysis of femoral head
collapse and thickened femoral neck
fractures
67
what are the two dysplasia seen in dogs?
hip and elbow
68
what causes hip dysplasia in dogs?
abnormal anatomy of femoral head and acetabulum
69
what are the two types of angular limb deformities?
valgus (lateral)
| varus (medial)
70
what are the potential locations of angular limb deformities in horses?
metaphysical growth plate
epiphysis
cuboidal bones
metaphysis
71
what dog breeds are predisposed to angular limb deformities?
small breeds (ShihTzu)
72
what causes angular limb deformities in dogs?
differential growth between bones - radius and ulna - (generally due to damage/trauma to toroth plates)
73
what causes flexural deformities of horses and cows?
disproportionate growth of tendons and its associated skeletal muscles
74
in horses, what fractures result in immediate euthanasia?
complete femur fracture
complete humorous fracture
complete tibia fracture
open, unstable fractures
75
how should horses with forelimb injuries be transported?
facing backwards
76
how should horses with hindlimb injuries be transported?
facing forwards
77
what rule must be followed when splitting a fracture?
stabilise joint above and below
78
what are compound fractures?
open (breaks the skin)
79
what are the three types of compound fracture?
1 - bone punctures through skin (treat as closed)
2 - open but minimal soft tissue damage and bone loss
3 - significant tissue damage and bone loss
80
what is a fracture?
disruption in the cortical continuity of bone (complete/incomplete)
81
what are the 4 As?
alignment
apposition
apparatus
activity
82
what does alignment mean regarding fracture repair?
joints need to be in line
83
what must be done when correcting a fracture surgically?
appose the forces acting on the fracture
84
what fractures are transverse?
any up to 30 degrees
85
what needs to be included when describing a fracture?
```
open/closed
bone
position
fracture line
degree of displacement
```
86
what ways can the position of a fracture be described?
articular
epiphyseal
growth plate
diaphyseal
87
how can fracture lines be described?
```
transverse
oblique
spiral
comminuted
segmental
```
88
what are avulsion fractures?
small pieces of bone pulled off at the point of tendon attachment
89
what classification system is used for growth plate (physeal) fractures?
salter-harris (I-VI) - lower the number the better the prognosis
90
what is a type I salter-harris fracture?
straight across the physis
91
what is a type II salter-harris fracture?
across physis and out through metaphysis
92
what is a type III salter-harris fracture?
across physis and out through articular surface
93
what is a type IV salter-harris fracture?
from articular surface through the growth plate to metaphysis
94
what are the two types of bone healing?
primary (direct)
| secondary (indirect)
95
what are the stages of secondary fracture healing?
```
haematoma
granulation tissue
connective tissue
fibrocartilage
bone formation (callus)
callus remodelling
```
96
what has to be done for direct bone healing to take place?
bone compressed against each other
97
what factors influence the healing on fractures in a positive way?
```
young patient (<8 months)
healthy
closed fracture
low energy
single injury
closed reduction
non-articular
```
98
what are the only fractures suitable for casting?
transverse fracture on the distal limb
99
what is the only force IM pins oppose?
bending
100
what are the disadvantages of IM pins?
poor at resting rotation or shear (shouldn't be used on their own)
interfere with medullary blood supply
101
what is the aim of cerclage wire?
give tight compression to bone
102
what fractures should cerclage wire be used for?
long oblique fractures
103
what are the uses of positional screws?
maintain relative position of two bone fragments
fasten plate to bone
anchor wire/suture to bone
lock an interlocking nail
104
what are lag screws used for?
create compression between bones (larger hole in near cortex so its pulled together)
105
what are the indications for external fixators (ESFs)?
```
long bone fractures
highly comminuted fractures
adjacent to other fractures
open/infected fractures
immobilising joints for soft tissue repair
corrective osteotomies
```
106
what are the advantages of external fixators?
inexpensive
| can adjust fracture after surgery
107
what is required for articular fracture healing?
rigid fixation
| early return to function (range of motion, avoid atrophy)
108
why is lameness in cattle important?
```
welfare (pain)
public perception
milk loss
reproductive loss
increased culling
nutrition (reduce DMI)
costs
```
109
what is the first step of managing lameness in cattle?
being able to measure it (mobility scoring and lesion recording)
110
what can hock scoring be used for?
determining how comfortable the environment is - predisposes to lameness
111
what is the proximal phalanx also known as?
fetlock bone
112
what is the middle phalanx also known as?
pastern bone
113
what is the distal phalanx also known as?
pedal bone
114
what is the lamellae of the cows foot?
leaflets of horn lining the inside of the wall
115
what is the laminae of the cows foot?
leaflets of connective tissue, collagen fibres, blood vessels and nerves that fit between the lamellae
116
what is the suspensory apparatus of the cows foot?
collagen fibres keeping the pedal bone and dermal lamellae attached
117
which claw of the hindlimb of cattle outgrows the other?
lateral outgrows the medial
118
what are the two methods of foot trimming in cows?
5 step dutch method
| dairyland method
119
how long should the dorsal wall length be trimmed to in cattle feet?
8cm (depending on size)
120
what should the sole depth at the toe be when trimming cattle feet by the dutch method?
7mm
121
what are arthritides?
conditions causing pain/dysfunction to joints
122
what is arthritis?
inflammation/degeneration of a joint
123
what is a diarthrodial joint?
specialised joint consisting of a synovial cavity allowing articulation of two or more bones
124
what is osteoarthritis?
degenerative condition ultimately leading to cartilage breakdown and loss of function
125
what is the function of a diarthrodial joint?
allow frictionless pain free motion
126
what makes synovial fluid?
ultrafiltration of plasma plus protein (hyaluronic acid)
127
what covers articular bones at joints?
hyaline cartilage
128
what makes up the fibrous joint capsule?
synovial membrane
nerves/blood vessels
supportive ligaments/tendons
129
what is articular cartilage made of?
extracellular matrix with some articular chondrocytes
130
what is responsible for the maintenance of the matrix of articular cartilage?
chondrocytes
131
what is osteoarthritis a disease of?
articular cartilage (other tissue also contributes)
132
what are some predisposing factors for osteoarthritis?
```
exercise/trauma
developmental orthopaedic disease
obesity
genetics
sepsis
repeated medication
ageing
```
133
what are the radiographic signs of osteoarthritis?
```
soft tissue swelling
osteophytosis
enthesiophytosis
subchondral bone sclerosis
intra-articular mineralisation
fragmentation
joint space collapse
subchondral bone cyst
```
134
what is osteophytosis?
new bone formation around the joint margin
135
what is enthesiophytosis?
new bone formation within soft tissue around the joint
136
what are the aims of osteoarthritis therapy?
analgesia
control articular inflammation
limit damage to articular tissue
promote healing
137
what is conservative therapy of osteoarthritis?
rest/restrict activity
weight loss
exercise (care)
138
what can be used to treat osteoarthritis medically?
NSAIDs
corticosteroids
hyaluronic acid
bisphosphonates
139
what are the three effects of NSAIDs?
anti-inflammatory
anti-pyretic
analgesic
140
how do NSAIDs work?
by COX inhibition
141
how do corticosteroids work?
bind to cytoplasmic and nuclear receptors - inhibit cytokines and alter signalling pathways
142
what effects does hyaluronic acid have on joints?
replaces synovial fluid
anti-inflammatory
analgesia
143
what effect do bisphosphonates have on joints?
inhibits bone resorption by inhibiting osteoclasts
144
what surgical treatments can be used for osteoarthritis?
arthroscopy (decried/flush)
joint replacement
arthrodesis
145
how does immune-mediated joint disease present?
polyarthritis (erosive/non-erosive)
146
what are most immune mediated joint diseases due to?
abnormal/inapproriate activity of immune cells and antigen presentation
147
what is the main part of the joint effected by immune mediated joint diseases?
synovium
148
what are the clinical signs of immune mediated joint diseases?
multiple limb joint pain/swelling, stiffness, lameness, pyrexia of unknown origin
149
what is the predominant cell seen following synoviocentesis of immune mediated joint diseases?
high neutrophil count
150
what changes to the blood could suggest an immune mediated joint disease?
```
anaemia
leucopenia
thrombocytopenia
raised globulins
low albumin
```
151
what drugs can be used to treat immune mediated joint diseases?
corticosteroids
152
what are some causes of infective arthritis?
bacteria - haematogenous, trauma/wound, iatrogenic
153
what is the response to infective arthritis?
marked inflammation - vasodilation and neutrophil influx with inflammatory cytokine/enzyme release
154
how does normal synovial fluid appear?
pale yellow and viscous
155
how does septic synovial fluid appear?
serosanguineous, turbid and reduced viscosity, increased volume
156
what is done to treat septic arthritis?
treat un darling cause
systemic/local antimicrobials
remove inflammatory mediators (lavage)
157
what causes Lyme disease?
Borrelia burgdorferi
158
how do dogs with Lyme disease present?
inflammatory non-erosive arthropathy
shifting lameness
swollen joints
159
what is used to treat Lyme disease?
doxycycline
160
what are the functions of tendons?
transfer force from muscle to bone (movement)
supports joint
store energy
161
what are the functions of ligaments?
attach/stabilise joints
protect tendons
proprioception
162
what is responsible for the maintenance and degradation of tendon/ligament extracellular matrix?
tenocytes/ligamentocytes
163
what are the two types of injury to tendons/ligament?
extrinsic (trauma)
| intrinsic (overload/degeneration)
164
what should be assessed when ultra sounding tendons/ligaments?
```
change in cross-sectional area
fibre echogenicity
margination
position
focal lesions vs generalised
acute vs chronic
blood flow (doppler)
```
165
define anechoic
no echogenicity (black)
166
define hypoechoic
reduced echogenecity
167
what are the three phases of tendon/ligament injury repair?
inflammatory
proliferative
remodelling
168
what are the clinical signs of the acute inflammatory phase of tendon/ligament injury?
lameness
pain
heat
swelling
169
what pathological changes are seen during the acute inflammatory of tendon/ligament injury?
haemorrhage
| inflammation (neutrophils, macrophage, oedema, increased blood flow)
170
what treatment can be used for the acute inflammatory phase of tendon/ligament injury?
```
cold therapy/NSAIDs (limit inflammation)
supporting bandage (limit further damage)
```
171
what clinical signs are associated with proliferative phase of tendon/ligament injury?
reduced lameness
resolution inflammation
tendon enlarged
172
what pathological changes are seen during the proliferative phase of tendon/ligament injury?
angiogenesis
| fibroplasia (fibroblasts and collage)
173
what treatment can be given during the proliferative phase of tendon/ligament injury?
splinting and stem cells (promote angiogenesis)
stem cells and physiotherapy (minimise scar formation)
exercise
174
what can be done if a tendon/ligament has been lacerated?
repair ends if feasible
175
what can be done if a tendon/ligament is part of an avulsion fracture?
reattach and cast
176
what are the clinical signs of chronic muscle injury?
stiffness, cramping, pain, atrophy, fibrosis/calcification
177
what biochemistry can be used in the diagnosis of muscle conditions?
serum muscle enzymes (CK/AST)
| urine (myoglobin)
178
what is CK in relation to serum muscle enzymes?
creatinine kinase
179
what diagnostic tools can be used for muscle conditions?
biochemistry
ultrasound
muscle biopsy
180
what is atrophy?
reduction in size
181
what can cause muscle atrophy?
disuse
denervation
cachexia
182
what are some causes muscle denervation?
```
trauma (laryngeal hemiplasia)
Myasthenia gravis (neuromuscular junction defect)
```
183
what must stay intact for a nerve to be able to reinnervate?
nerve sheath
184
what is muscular hypertrophy?
increased muscle bulk due to larger fibres (increased workload)
185
what are the three main types of muscular degeneration?
cellular swelling
hyaline degeneration
granular degeneration
186
what can cause cellular swelling of muscles?
minor chemical imbalances within the muscle (Na/K)
187
what does hyaline degeneration of muscles effect?
sarcoplasm
188
what myopathy often causes hyaline degeneration?
nutritional myopathy
189
what happens if there is irreversible damage to muscle tissue?
calcification
190
how is circulatory disturbances to muscle compensated?
collateral circulation
191
what causes white muscle disease?
selenium/vitamin E deficiency
192
what are the clinical signs of white muscle disease?
muscle weakness/stiffness
recumbency
arrhythmia/murmur if myocardial effected
193
what species is white muscle disease seen in?
cattle (calves)
194
what causes stiff lamb disease?
selenium/vitamin E deficiency
195
what is exertional rhabdomyolysis due to?
unfit horses (not been excised over the weekend)
196
what are the clinical signs of acute exertional rhabdomyolysis?
stiffness to severe pain
197
what muscles is acute exertional rhabdomyolysis seen in most commonly?
gluteal
semitendinosus
semimembranosus
198
what dog breeds is eosinophilic myositis seen in?
large breeds (German shepherds)
199
what muscles are effected by eosinophilic myositis?
temporal/masticatory muscles (enlarged)
200
what is used to treat eosinophilic myositis?
corticosteroids
201
what animals is atypical myoglobinuria seen in?
horses
202
what are the clinical signs of atypical myoglobinuria?
fatal
muscle weakness/recumbency
increased CK/AST
(widespread necrosis)
