Dogs and Cat 6 Flashcards

1
Q

Fracture reduction direct and indirect ways

A
  • Direct:
    ○ Traction/leverage on major bone fragments
    ○ Requires an open approach
  • Indirect:
    ○ Traction remote from fracture site often via ligaments and tendons (ligamentotaxis)
    ○ Can be performed closed or via minimally invasive techniques
    ○ Pins and Fracture distractor
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2
Q

Internal fixation goal and advantages and disadvantages

A
  • Want to hold the alignment in place to allow animal to weight bear after surgery
    ADVANTAGES
  • May allow complete reconstruction of the bony column and load sharing
  • If applied correctly results in rigid stability allowing rapid weight bearing and minimizing fracture disease
  • Typically very comfortable for the patient and minimal aftercare
    DISADVANTAGES
  • Invasive: requires a surgical approach for application plus implants potentiate infection
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3
Q

Areamoment of inertia for internal fixation what is it, formular and therefore what dimentions have greater

A
  • Property of a material (e.g. Stainless steel) to resist bending forces = Area Moment of inertia
  • AMI of a rod ∝ Radius4
    ○ Small increase in radius -> large increase in AMI
    § Want to get large pin - greater resistance to bending forces
    ○ So 4mm pin AIM = 16, 6mm pin AIM = 81
  • AMI of a plate ∝ Height3
    ○ Thicker plate resistance to bending
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4
Q

Intramedullary pins where placed what resist and don’t resist, benefits and how to choose pin size and what can use with

A
  • Placed in the central axis (medullary canal) of bones
  • Mighty resistors of bending
  • Inexpensive and low inventory requirement
  • Will not prevent axial compression, rotation, shear
  • When placed alone (uncommon) select pin approximating 70% of IM canal diameter
  • When used with a plate an IM pin of 50 % of medullary canal diameter will extend plate fatigue life 10 fold
    ○ IM supplies bending, plate provides contraction of compression and rotation
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5
Q

Intramedullary pins how to introduce into bone

A

○ Placed via a Jacobs chuck or a drill
○ Can be placed:
§ Normogradeor Retrograde (from the fracture site)
§ IM pins can be placed retrograde or normogradein the humerus, ulna and femur
§ IM pins can be ONLY be placed normogradein the tibia
§ IM pins cannot be placed in the radius

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6
Q

Kirschner wires and cerclage wiring what used for

A

INTERNAL FIXATION
Kirschner
- Primary stabilization for very stable fractures in young/small patients
- Achieving temporary stabilization
- As an adjunctive implant
- 2 points fixation required to prevent rotation
Cerclage
- Wire encircling the entire bony diameter to create compression
- Only suitable for long oblique fractures or spiral fractures.
- Only works with perfect anatomical reconstruction
- Need a minimum of 2 and ideally more

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7
Q

Orthopaedic wire how acquire strength, knots and application

A
  • Strength is related to cross sectional area - need to twist around each other
  • Knots:
    1) Single loop cerclage
    2) double looped cerclage
    Applications
    ○ Tension band wiring: - most common
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8
Q

Screws what are the 2 main types, differences and which most common

A
1) Cortical bone screws: - most common 
§ Designed for dense cortical bone.
§ Increased pitch (No. Threads/length)
§ Less thread depth
§ Greater core diameter
2) Cancellous bone screws (metaphysis only)
§ Designed for cancellous bone
 Decreased pitch
§ Increased thread depth
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9
Q

what are the 3 ways screws are placed and what does this result in

A

1) As positional screws:
§ Only results in fixation of the two fragments without compression
2) As a lag screw: - generally cortical screw
○ Creates compression across a fracture which markedly increases stability -> Achieves this by
□ Glide hole (first hole) - is drilled into cortex of one of the fracture pieces and has a larger diameter to the screw - so screw does not engage in this cortex
□ Second ‘pilot’ hole then drilled from the glide hole into the second fracture piece HOWEVER the diameter is equal to that of the screw so the screw engages with this cortex resulting in compressive force
Compression from screw in bottom piece and top of screw head in the top forces the fracture sites together
3) through plate

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10
Q

What are lag screws suitable for and rules for placement

A

○ Suitable for oblique fractures.
○ Ideally screw should be placed perpendicular to fracture
○ Need 5 cortices at each end of the fracture site -> can have two cortices if go through both surfaces

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11
Q

Bone plates advantages and disadvantages

A

ADV
1. neutralises all fracture forces
2) can be applied minimally invasively
3) Can achieve maximal stability of fracture gap with dynamic compression plating,
4) Very rapid return to function with minimal post op pain and care
DIS
1) traditional rewuires extensive dissection
2) plate perioheral to mechanical axis
3) accurate contouring of the plate to the bone surface

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12
Q

Conventional plating what does stability require, minimum of how many cortices and clinical results

A
  • Stability for this type of plate relies on friction between the plate, bone and screw
  • Minimum of five cortices above and below the fracture
    ○ Generally 2.5 screws
  • Very good clinical results.
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13
Q

What are the 5 main ways to apply plate to bone and what size bone plate do you choose

A

1) dynamic compression plate
2) Neutralisation plate
3) bridging plate - span communicable fracture site
4) buttress plate - just hold fragments in place
5) locking plate - cotouring plate not required, better stability and rigid, more biological approach
SIZE - <30% bone diameter

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14
Q

Dynamic compression plate what does it have and therefore the 2 types of screws

A

○ Have an oval hole so two ways can use screws within
§ Compression -> Fracture anatomically reconstructable - results in compression at fraction site - eg: Transverse fracture
□ Use cortical screws with dynamic plate and drill eccentrically (off to one side of the plate hole), screw wants to be in the middle so will move slightly bringing the fracture site together
§ Neutral -> screw straight down the middle of the oval hole so no compression

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15
Q

Interlocking nails what is it, good at resisting and applicable to fractures of

A
  • Like an IM pin with holes
  • Good at resisting bending
  • Screws/bolts prevent axial compression or rotation
  • Can be placed minimally invasively with the aid of fluoroscopy
  • Applicable to fractures of:
    ○ Femur
    ○ Humerus
    ○ Tibia
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16
Q

external skeletal fixation what good for and goal

A

good for Gardiner approach of fracture repair

- Frame: Supportive exoskeleton for the healing fracture.

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17
Q

Linear external skeletal fixation what are the types of pins

A
  1. Smooth: now largely superseded
  2. Positive profile:
    § Threads rolled on, thread diameter > core diameter
    § Better engagement
  3. Negative profile:
    § Threads cut in, thread diameter = core diameter
    § Stress riser
  4. End threaded half pins: - half pin
    § Only go through soft tissue on one side of bone
  5. Centred threaded full pins: - full pins
    § Go through soft tissue on both sides of bone
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18
Q

Linear external skeletal fixation principles what forces resist, dependenat on and the 3 types

A
  • Can resist all fracture forces: - like plates
    ○ Bending
    ○ Axial (Compression/distraction)
    ○ Rotational
    ○ Shear
  • Dependant on configuration:
    ○ Bending most effective in the same plane as the fixator frame.
  • Different types
    ○ Type 1 -> unilateral, uniplanar
    ○ Type 2 -> unilateral, biplanar -> two connecting bars at right angles to each other
    ○ Type 3 -> strongest, type 1 and 2 -> three connecting bars, two at 180 degrees and 1 at 90 degrees
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19
Q

Linear external skeletal fixation advantages and disadvantages

A

ADV
- versatile and adaptable
- well tolerated, particularly on distal limbs
– Implants are removed (easily) once fracture has healed –useful in contaminated/open fractures
- Frame can be adjusted post surgery to improve alignment or enhance fracture healing
- Implants are cheap vs plating
- Biologically friendly to extraosseoussoft tissue and blood supply for fracture healing
DIS
– Increased morbidity/decreased limb use compared with internal fixation
Draining Pin tracts:
○ Consequence of percutaneous elements transfixing skin and other soft tissues
- Increased patient care required by owner and clinician compared to internal fixation

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20
Q

Linear external skeletal fixation how to apply and how to increase frame strength/stiffness

A
  • Frame needs to be strong/stiff enough to withstand forces applied during normal activity
  • Frames should be applied with strict aseptic technique.
    Can increase frame strength/stiffness by:
    ○ More pins: Minimum of two, ideally 3 per fragment, beyond 4, advantage is negligible
    ○ Bigger pins:
    ○ Decreasing pin working length (distance between clamp and bone) by getting clamp close to bone :
    ○ Span the fragment with pins (far, near, near, far principle).
    ○ Use threaded pins rather than smooth
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21
Q

Linear external skeletal fixation aftercare

A
  • Entire limb should be bandaged to reduce swelling.
  • Sponges packed under the frame.
  • Frame wrapped to reduce the risk of fixator snares
  • ESF specific complications-
  • Pin track discharge:
    ○ Especially an issue in areas with more soft tissue
    ○ May reflect instability
    ○ Often leads to infection, some cases require oral antibiotics
    ○ Cleaning the skin with chlorhexidinesurgical scrub
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22
Q

Open fractures what fixation device need to use and why and inital emergency treatment

A
○ Use external not internal fixation - IMPORTANT 
§ Internal plate will be able to create a biofilm to harbour infection - leads to bone infection 
Initial emergency treatment:
○ Lavage and debridement
○ C&amp;S
○ Commence intravenous antibiotics
○ Sterile dressing
○ Apply external coaptation
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23
Q

What are the 4 properties of a successful bone graft

A
  1. Osteogenesis
    § Surviving graft osteoblasts produce new bone
  2. Osteoinduction
    § Chemical signalling from growth factors induce differentiation of pleuripotent mesenchymal cells into osteoblastic/chondroblastic lineage
  3. Osteoconduction
    § Microstructural support for deposition of bone
  4. Osteopromotion
    § Structural support
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24
Q

Autogenous cancellous bone graft and cortical grafts when used and which is better as provides which properties

A

Autogenous cancellous bone graft:
- Proximal humerus, ilialwing or proximal tibia.
- Remains the gold standard treatment
- Transferred as quickly as possible
- all 4 properties
Cortical grafts:
- Mainly used where a large bony defect exists
- Osteoinductive and osteoconductive & provide structural support

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25
Q

Postoperative management for fracture repair

A
  • Lead walking only and cage rest
  • Abdominal sling
  • Owners are frequently poorly compliant
  • Weightbearing on the operated limb is desired and encouraged.
  • Adequate analgesia
  • Ice packing
  • Typically patients are discharged with an NSAID +/-Tramadol
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26
Q

What are the 4 factors to assess post-operatively after fracture repair

A
1. Alignment
○ both angulation and rotation.
○ Joint to joint alignment 
○ Fracture alignment 
2. Apposition:
○ Size of fracture gap
3. Apparatus
○ Is there sufficient purchase?
○ Does an IM pin engage the metaphysealtrabeculae?
○ do implants impinge on joints?
○ could implants impinge on adjacent ST?
○ Any problems with surgical stabilisation can then be immediately addressed- •
4. Activity
○ Bone healing 
○ 6-8 weeks later take radiograph to determine
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27
Q

What are the 3 types of arthritis

A
  1. Osteoarthritis
  2. Infective arthritis
  3. Immune mediate arthritis
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28
Q

Osteoarthritis causes and 4 factors that may influence

A
- Primary:
○ no inciting cause
○ more common in cats than dogs
- Secondary:
○ Underlying cause:
§ Articular fracture
§ Developmental/degenerative conditions
§ Changes that alter the way load is transmitted through the joint:
□ Ligamentous injuries
□ Angular limb deformities
Factors that may influence 
	1. Age
	2. Obesity 
	3. Neutering 
	4. Life style
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29
Q

Osteoarthritis pathogenesis 3 steps and history and clinical signs

A
Pathogenesis 
1. Synovitis 
2. Subchondral bone 
3. Pain 
History and clinical signs 
1. Lameness/stiffness 
2. Signs exacerbated by vigorous activity 
3. Reduced activity/exercise intolerance 
4. Signs improved with NSAIDS 
5. Reluctance to jump, climb stairs 
6. Licking at affected joints 
7. Aggression/irritability
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30
Q

Osteoarthritis diagnosis

A
  1. Radiographs
  2. Synovial fluid analysis:
    ○ Assess volume, colour, turbidity & viscosity
    ○ Mild increase in cell count (2-5 x 109/l <2 for normal),
    ○ Predominantly mononuclear cells
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31
Q

Osteoarthritis conservative management list the 6 main things involved

A

1) weight loss
2) excercise modulation - levels constant, swimming or hydrotherapy ideal
3) NSAIDS
4) other drugs - paracetamol, tramadol, codeine and oral opiods, corticosteroids
5) nutraceuticals - disease modifing osteoarthritis drugs, glucosamine, essential fatty acids
6) regnerative medicine - stems cells

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32
Q

NSAID use in osteoarthritis what does it do and side effects

A
○ Block the cyclooxygenase pathway
§ Leads to formation of thromboxanes and prostaglandins 
§ COX 1 - constitutive form 
§ COX 2 - inducible form  
○ Side effects 
§ Gastroduodenal damage/ulceration 
§ Reduced renal blood flow 
§ Reduced platelet function
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33
Q

Other drugs used in treatment of osteoarthritis

A

○ Paracetamol:
§ Centrally acting
§ Improved GI and renal safety profile c/w NSAID’s
§ For Dogs ONLY, HIGHLY TOXIC/FATAL IN CATS
○ Tramadol:
§ Synthetic opioid
○ Codeine and oral opioids:
○ Amantadine:
§ MMDA (3-methoxy-4,5-methylenedioxyamphetamine) antagonist
○ Corticosteroids:
§ Intra-articular preparations
§ deleterious effects on cartilage matrix synthesis

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34
Q

Nutraceuticals what are hte main ones used in osteoarthritis and evidence supporting their use

A
1) Disease modifying ostoeoarthritis drugs (DMOADs):
§ Pentosan Polysulfate:
□ In vitro positive effect on cartilage
□ Fibrinolytic and thrombolytic effects,
□ Some evidence to support efficacy in dogs
2)  Nutraceuticals:
§ Glucosamine and chondroitin:
□ No evidence to support efficacy
□ Expensive
□ Safe
3)  Essential fatty acids:
§ Eicosapentaenoic acid (EPA)
§  significant effect based on force plate analysis.
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35
Q

Regenerative medicine use in osteoarthritis and evidence

A

○ Stem cells:
§ Harvested from autologous adipose tissue then expanded and injected intraarticularly
§ allogenic
§ Mechanism unknown
§ No evidence (so far)
§ Some anti-inflammatory effects for a short period

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36
Q

Salvage surgery for osteoarthritis when used and the 4 options

A
  • If refractory to medical management
    1. Excisional arthroplasty
    2. Arthrodesis
    3. Total joint replacement
    4. Amputation – rule out other limb pathology before cut
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37
Q

Infectious/septic arthritis what are the 3 types, causes and common organisms in dogs vs cats

A
Classification 
- Type 1 (acute)
- Type 2 (chronic)
Causes 
- Iatrogenic (Surgery/arthrocentesis):
- Penetrating wound 
- Bite wounds
- Hematogenous
Typical organisms 
- Dogs:
○ Staphylococcus, betahemolytic streptococcus
- Cats:
○ Pasteurella and Bacteriodes
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38
Q

Infectious/septic arthritis pathogenesis and clinical signs

A
Pathogenesis 
- Rapid infiltration of the synovium and joint fluid with suppurative inflammatory cells
- Release of inflammatory cytokines and proteolytic enzymes
- Rapid degradation of collagen and glycosaminoglycan
- Changes are rapid and irreversible
- Fibrin deposition
Clinical signs 
- Acute onset severe lameness (type 1)
- Marked swelling/effusion
- Warmth and pyrexia
- Lymphadenopathy
- Systemic signs
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39
Q

Infectious/septic arthritis diagnosis what are the 2 main techniques used and what looking for on each

A
1. Arthrocentesis 
○ High cell count: >50 x 109/l
○ Predominantly neutrophils (80-90%) with toxic change
○ Intracellular bacteria
○ Culture: Negative in 80-90%
○ Synovial fluid should be inoculated into blood culture medium
○ Synovial biopsy: equivalent positive culture rates
2. Radiography 
○ Joint swelling
○ Gas
○ Bone lysis, periosteal reaction
○ Radiographic changes take 2 weeks
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40
Q

Infectious/septic arthritis what are the 2 main treatment options and prognosis

A
- Broad spectrum antibiotics:
○ Intravenous initially
○ Only AFTER synovial fluid sample taken
○ Minimum of 28 days
○ Cessation based on synovial fluid analysis
○ If no improvement within 24-48 hours consider surgery
- Surgery - joint irrigation surgery 
○ Indicated if:
§ Gross contamination
§ Poor response to initial antibiotic therapy
§ Implant retrieval required
- Prognosis:
○ Guarded
○ OA long term
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41
Q

Immune mediated arthritis pathogenesis/cause

A
  • Not completely understood
  • Phagocytosis of immune complexes under chronic antigenic stimulus
  • Recurrence/persistence of the inciting antigen lead to recurrence of clinical signs
  • Immune mediated problems affecting other body systems may coexist
42
Q

Immune mediated arthritis what are the 2 classification and causes/ forms within

A
Classification 
1. Erosive:
- Rheumatoid
- Erosive polyarthritis of Greyhounds
- Periosteal proliferative polyarthritis of cats
2. Non-Erosive:
- Idiopathic (Type 1) - 50%
- Secondary to:
○ Remote infection (Type 2) - 25%
○ GI Disease (food/bacterial Ag’s, Type 3) - 15%
○ Neoplasia (Type 4) - rare
○ Systemic lupus erythematosus
○ Drugs - sulfonamide
- Breed related syndromes
- Periosteal proliferative polyarthritis of cats (non erosive forms)
43
Q

Immune mediated arthritis history and clinical signs

A
  • Typically multiple joints
  • Typically more distal joints
    ○ Most common are: elbow, carpus, stifle and hock
  • Lameness, stiffness, inactivity
  • Effusion and periarticular swelling
  • Pyrexia
  • Systemic signs
  • Periarticular swelling and fibrosis
  • Lymphadenopathy
44
Q

Immune mediated arthritis what are the 3 main diagnostic techniques and what looking for

A
  1. Arthrocentesis:
    ○ Markedly elevated cell count, predominantly neutrophils
    ○ Submit for culture – rule out infection
    ○ At least four joints
  2. Synovial biopsy:
    ○ When difficult to obtain joint fluid
  3. Radiography of joints:
    ○ Unremarkable - non-erosive forms
    ○ Bone lysis, subluxation/luxation, deformity - erosive forms
    ○ Rule out other causes - neoplasia
45
Q

Immune mediate arthritis what are the 3 main treatment options

A
  1. Treat inciting cause
  2. Medical treatment is typically continued for several months then tapered and ceased.
    - Prednisolone:
    ○ 1st line drug- 2-4 mg/kg
    - Other immunosuppressive drugs:
    ○ Indicated when:
    § Refractory to pred
    § Severe pred related side effects
    § Erosive/multisystemic disease necessitating aggressive approach
  3. Surgery:
    ○ Occasionally used for joint salvage
46
Q

Cruciate disease what are the 2 main causes of injury, how common and pathogenesis

A

1) Traumatic (acute):
- Acute history of traumatic event
- Rare
- Hyperextension of the stifle
- Internal rotation of the tibia
- Avulsion fracture rather than torn ligament
2) Chronic/degenerative (cruciate disease):
- Typically in middle aged large breed dogs but as young as 9 months old
- Chronic history
- Radiographic OA
- Pathogenesis is not completely understood
○ Abnormal conformation
○ Incidence higher in spayed females
○ Autoimmune basis?
○ Genetic basis?

47
Q

Cruciate ligaments anatomy and 5 main functions

A

The cranial cruciate ligament has two bands
○ Craniomedial band:
§ Tense in all angles
○ Caudolateral band:
§ Tense during extension, lax in flexion
Function - important
1. Limit cranial tibial subluxation
2. Limit hyperextension
3. Limit internal rotation of the tibia
4. Mechanoreceptor - nerve innervation -> prevent overextension of the knee joints
5. Both ligaments help provide valgus/varus stability during flexion

48
Q

menisci of stifle 5 reasons why so important and where medial and lateral attach and therefore which more prone to injury

A
  1. Joint lubrication
  2. Load bearing
  3. Load distribution
  4. Shock absorption
  5. Joint stability
    - Medial meniscus firmly attached to the tibia and moves with the tibia – impinged by the femoral condyle when the joint is instable
    ○ If have tibial issues -> lead to issues of the medial meniscus -> also not attached to the joint space so doesn’t move when that does
    - Lateral meniscus more attached to the femoral condyle and moves with the femur
49
Q

Concurrent meniscal tears with cruciate injury where generally occurs and why and clinical signs

A
  • Very common
    ○ In the caudal horn of the medial meniscus
    § Condyle will pinch out the caudal condyle of the meniscus
  • Painful
  • The most common type of tear - bucket handle tear
  • Meniscal clicking during range of motion
  • Meniscal tears can also occur in isolation and post cruciate surgery
50
Q

What is the history and clinical signs of dogs with cruciate disease

A
  • Lameness
  • Positive ‘sit’ test
  • Pain
  • Palpable effusion
  • Biceps atrophy
  • Medial buttress
  • Dogs with concurrent bilateral acute ruptures may mimic spinal disease
51
Q

Manipulative tests for cruciate ligamanet injury what are the 2 main ones and how to perform

A
  1. Cranial drawer
    ○ Important to test in flexion and extension
    ○ Puppy drawer
    Need to grasp the bony parts
    - Bottom hand - Index finger on tibial tuberosity and thumb on fibula head
    - Top hand - index finger on patella and thumb on lateral fabella
    - Can be very painful in positive animals -> may need to sedate or anaesthesia
    Extension and flexion testing for
  2. Cranial tibial thrust
    ○ May not be present in all partial ruptures
    ○ Thickened fibrous synovium may prevent thrust
    Normally would put finger over the patella however if full cruciate will be obvious
52
Q

Cruciate injury diagnostic imaging

A
  • Effusion on the mediolateral view:
    ○ compression of the infrapatellar fat pad
    ○ bulging of the joint capsule caudally
  • Periarticular osteophytes
  • Subluxation of the tibia cranially
  • Ultrasound, MRI and contrast arthrography/CT
53
Q

Cruciate disease diagnostic imaging and arthrotomy/arthroscopy when used

A
  • Effusion on the mediolateral view:
    ○ compression of the infrapatellar fat pad
    ○ bulging of the joint capsule caudally
  • Periarticular osteophytes
  • Subluxation of the tibia cranially
  • Ultrasound, MRI and contrast arthrography/CT
    Arthrotomy/arthroscopy
  • Confirmation of the diagnosis - should always been done before surgery
    ○ Partial/complete rupture
  • Damaged meniscus (partial, hemi- or complete meniscectomy)
    ○ Meniscal release -> prevention for meniscal injury after surgery
    § Release the caudal part of the medial meniscus
54
Q

Cruciate disease conservative managment and which need surgical intervention

A
  • Cage rest and NSAIDs
  • Physiotherapy/hydrotherapy
  • Cats and small dogs <15 kg without surgical intervention -> can do well but generally just recommend surgery
    ○ Without meniscal tear
  • If persistent lameness, consider surgery
  • Acute worsening may be meniscal injury
55
Q

How to restore cruciate stability intracaspular vs extracapsular

A

1) Intra-articular techniques
- Using grafts - doesn’t always work in animals due to high prevalence of inflammation
- Inferior results compared to other procedures
2) Extra-articular techniques
- Using synthetic suture material to mimic the path of the CCL
- Suture material is typically anchored behind the lateral fabella then through bone tunnels in the tibial tuberosity
- Nylon leader line (fishing line)
- Multifilament suture materials
○ WILL EVENTUALLY FAIL
- Tightrope (quasi isometric) bone to bone -> much more secure less commonly used in larger animals though due to body weight

56
Q

Geometry altering procedures what are the 4 main ones used and average tibial plateau angle due to what

A
  1. Tibial plateau levelling osteotomy (TPLO) - MOST IMPORTANT
  2. CORA-based levelling osteotomy (CBLO)
  3. Tibial tuberosity advancement (TTA) - also used
  4. TWO and TTO
    Osteotomy: BIOMECHANICS
    - Average TPA (tibial plateau angle) in dogs is 24 degrees
    - Due to the caudally directed slope of the tibia, on weight bearing cranial tibial thrust is created
    - No CCL: subluxation:
57
Q

TPLO biomechanics what done, what provides stability and advantages

A
  • Plateau rotated down to 6 degrees: cranial tibial thrust eliminated but tibial drawer test still positive as don’t fix the ligament
  • Hamstring muscles can now provide adequate stability to prevent cranial tibial luxation during weight-bearing
  • Advantages:
    ○ earlier return to weight bearing
    ○ low rates of subsequent meniscal tears
    ○ quicker return to function and better long term function
58
Q

Tibial tuberosity advancement what is done, how stabilised and complications

A
  • Advancement of tibial tuberosity: tibial plateau is perpendicular to the straight patella tendon - less invasive
  • Tibial tuberosity osteotomy
  • Tuberosity advanced and stabilized with a titanium cage and a titanium plate
  • Osteotomy does not involve weight bearing axis
  • Higher rate of subsequent meniscal tears in clinical studies compared with TPLO
  • Recent research showing subluxation occurs during weight bearing - causing postliminary meniscal injury? Unstable
59
Q

Aftercare for cruciate injury and timeline for recovery

A
  • Cage or room rest with lead walking only.
  • NSAIDs +/- Tramadol +/- Gabapentin
  • Hydrotherapy and physiotherapy
  • Prognosis for a return to normal function is good
  • OA progression - ALWAYS - don’t address primary cause
  • Acute lameness:
    ○ Postliminary meniscal injury
    ○ Infection
    ○ Implant failure
    Recovery timeline
    1. Ice pack for 3 days initially - after that heat pack
    2. After a few days have passive range of motion in the stifle
    3. After 2 weeks of strict no exercise if everything okay gradually increase exercise
    ○ 5 min increase every week for 8 weeks
    8 weeks post-operative bring back in for radiographs
60
Q

muscle/tendon strain what are the 3 main classifications

A
  • Grade 1: inflammation, pain, swelling or myositis and bruising, fibres intact - functional -> no surgery needed
  • Grade 2: tearing of some fibres, still functional - grey zone, mild - no surgery but severe - probably surgery
    ○ Determine treatment via orthopaedic examination and how stable the joint is
  • Grade 3: complete torn ligament or muscle fibres, non-functional – surgery
61
Q

Shoulder instability what generally results from, medial or lateral instability more common, diagnosis and treatment

A
  • Bony anatomy normal
  • Stretching/tearing of medial soft tissue constraints
  • Degenerative and Congenital forms
  • < 80% are medial instability
  • Definitive diagnosis by MRI or arthroscopy -> too painful for proper orthopaedic exam unless sedated
    ○ Radiograph - NO due to superimposition in this area, US -> NO as cannot penetrate bone properly
  • Surgical reconstruction with velpaeu sling (5-6 weeks - non-weight bearing sling)
62
Q

Traumatic elbow luxation pathogenesis, clinical examination and radiogrpahy

A

PATHOGENESIS
- 90% are luxating laterally
○ High impact exercise, dog fights, RTA
CLINICAL EXAMINATION
- Non-weight bearing lameness with pain
- The elbow in flexion with the antebrachium externally rotated and abducted
- Lateral epicondyle less distinct
- Radial head and olecranon positioned laterally
RADIOGRAPHY
- Direction of luxation classified on the location of the radius and ulna relative to the humerus
- Observe closely for avulsion/articular fractures and OA
- Open reduction is indicated

63
Q

Carpal hyperextension injury what level, 2 main causes and treatment

A
  • Injury may be at the level of the antebrachiocarpal, intercarpal or carpometacarpal joints
  • Cause:
    ○ Acute: a fall or jump from height
    ○ Chronic: ligament degeneration
  • Treatment: Arthrodesis
    ○ Permanent coaptation (Orthosis) for nonsurgical patients
    ○ Pan or partial carpal arthrodesis, depending on the site of injur
64
Q

coxofemoral luxation pathogenesis and radiography

A

PATHOGENESIS
- Usually secondary to major trauma.
- Spontaneous luxation
- Most common direction is craniodorsal (73-78% of cases)
RADIOGRAPHY
- Orthogonal views of the pelvis
○ Which direction the luxation is -> craniodorsal or ventral -> NEED TO KNOW FOR TREATMENT AS DIFFERENT
- Look closely for concurrent fractures before reduce back into joint
○ Avulsion of the attachment of the ligament of the femoral head
○ Greater trochanteric fractures
○ Femoral neck fractures
○ Acetabular fractures
○ Capital physeal fractures
- If concomitant HD (hip dysplasia), salvage procedures are indicated – FHO, THR

65
Q

Coxofemoral luxation clinical exam and conservative management

A

CLINICAL EXAMINATION
- Craniodorsal luxation: the limb shorter, stifle adducted and externally rotated.
- Ventral luxations: limb appears longer, abducted and internally rotated, greater trochanter difficult to palpate.
- Swelling, pain, crepitus
- Position of greater trochanter is a marker relative to ilial crest and ischial tuber
- Thumb displacement test
CONSERVATIVE MANAGEMENT
- Most likely to be successful if no underlying pathology and recent luxation
- Closed reduction
- Prevention of recurrence:
○ Craniodorsal luxation:
§ Ehmer sling - flexes hip joint and abducts and internally rotates the femur to position the head within the acetabulum
○ Ventral luxation:
§ Hobbles -> ropes/bandages that prevent lib abduction and maintain joint reduction

66
Q

Coxofemoral luxation surgical repair methods what are the 3

A
  1. Toggle
    - Most common procedure
    - Mimic the ligament of the femoral head
    - Toggle in the pelvic canal
  2. Transarticular pin
    - Pin driven from fovea capitis to third trochanter similarly to bone tunnel described for toggle.
    - Hip reduced and pin driven through acetabular wall
    - Pin removal at 3 weeks
  3. Prosthetic capsulorrhaphy
    - Suture anchors or screws and washers in dorsal acetabular rim
    - Two separate sutures connected through two anchorage points and bone tunnel in dorsal femoral neck.
    - To mimic dorsal joint capsule
67
Q

Collateral ligament injuries of the stifle pathogenesis and diagnosis

A
PATHOGENESIS
- Secondary to trauma
- Isolated injuries uncommon
- More likely multiple ligament injuries
DIAGNOSIS
- Collateral integrity tested with the stifle in extension -> under general anaesthesia - VERY PAINFUL 
- Varus stress for lateral collateral
- Valgus stress for medial collateral
68
Q

Collateral ligament injuries of the stifle surgery and aftercare

A

SURGERY
- Stifle luxation -> arthrotomy
- Meniscal tears and cruciate ligament as par cruciate surgical management
- Collateral ligament injuries:
○ Primary repair: locking loop pattern (A)
○ Prosthetic ligament in all cases (B-D) is indicated
- Transarticular pin at 135 degrees for 3-4 weeks
AFTERCARE
- Cage rest with lead walking only for 6 weeks
- NSAIDs
- Functional prognosis is good
- OA progression

69
Q

Talocrural luxation what are the 3 things instability is a result of, how to repair and prognosis

A
  1. Malleolus avulsion fractures:
    - Open reduction and tension band wire
    - Immobilization for 6 weeks with splint or transarticular ESF
    - Better prognosis
  2. Collateral ligament rupture
    - Primary repair of ligaments
    - Protection of primary repair with prosthetic ligament
    - Immobilization for 6 weeks with splint or transarticular ESF
  3. Shearing injury
    - Contaminated, significant tissue loss - common in traffic accident
    - If significant articular cartilage damage consider going straight to Pantarsal arthrodesis
    - Transarticular ESF for 6 weeks
    - Due to extensive fibrosis transarticular ESF (external fixative) is often enough on its own – no ligament reconstruction with prosthesis
    ○ If residual instability post frame removal -> prosthetic ligaments
    - Prognosis good
70
Q

Medial collateral ligament of the tarsus what are the parts, what do they stabilise and therefore how to find out which part affected

A

Medial collateral ligament -> has long and short part
- Long part stabilise joint when extended
- Short part stabilise joint when flexion
Therefore when examining can find out which part affected
- Extension issue then long part issue
- Flexion issue then short part issue
Long parts are absent in the cat

71
Q

common calcanean tendon injury pathogenesis what are the 3 tendons involved and the 2 main causes

A

Three individual tendons:- IMPORTANT
• Gastrocnemius
• Superficial digital flexor
• Combined tendon - semitendinous, biceps
- Traumatic
○ Typically complete transection or avulsion
○ Often a wound visible
- Chronic/Degenerative:
○ Middle aged Labrador Retrievers, pointers, and Dobermans
○ Often the gastrocnemius affected close to the insertion on the calcaneus
○ SDFT intact (50%)
○ Palpation: thickened, painful distal tendon
○ Radiography, u/s -> arrangement of fibres

72
Q

common calcanean tendon what is the surgery

A
  • Tendon repair:
    ○ Individual tendons repaired separately if possible
    ○ Tendons sutured with tension relieving patterns eg. Three Loop Pulley vs other suture patterns
    ○ Monofilament non-absorbable (ie, polypropylene)
    ○ Transverse bone tunnel in calcaneus in case of avulsion or close to the calcaneus
73
Q

common calcanean tendon post operative management and prognosis

A
- Immobilisation: - most important 
○ Mandatory
○ For 6 weeks
○ Methods:
§ Splint
§ Transarticular ESF
§ Calcaneotibial screw
- Pan tarsal arthrodesis
Prognosis is good
74
Q

Biceps tendinopathy signalment, clinical signs, diagnosis and treatment

A
- Signalment:
○ Middle - older age
○ Medium - large breed
○ Primary or secondary
- Clinical signs:
○ Weight bearing lameness
- Diagnosis:
○ Manipulation:
○ Imaging:
§ Radiography, contrast arthrography, U/S, MR, arthroscopy
- Treatment:
○ Long acting cortisone injection
○ Tenodesis or tenotomy
75
Q

Quadriceps contracture when generally occur, risk, clinical signs, causes, prevention and prognosis

A
  • After fracture of the distal femur, particularly in young growing dogs
  • Risk:
    ○ The limb is not used or the stifle is immobilized after fracture repair
  • Clinical signs:
    ○ The stifle joint cannot be flexed, atrophy of quadriceps musculature, patient with extended straight hind limb
  • Causes:
    ○ Fibrous replacement of the muscle fibres as a primary change
    ○ Adhesion between muscle and bone as secondary changes, along with periarticular fibrosis and eventual joint ankyloses
  • Prevention: - most important
    ○ Early recognition and restoration of mobility by extensive physiotherapy
    ○ 90/90 bandage
  • PROGNOSIS - VERY BAD
76
Q

Infraspinatus contracture clinical signs, is it painful, treatment and prognosis

A
  • Acute lameness 4- 6 weeks prior to develop clinical signs
  • Abnormal gait with Rotation and limited ROM
  • Usually not painful
  • Treatment -> Release of the infraspinatus muscle
  • Prognosis is good
77
Q

What are 8 important things to determine on a musculoskeletal radiography

A
  • Good radiographs -> place?, exposure and contrast?, location?
  • Species
  • Radiographically immature or mature
    ○ Growth place open or closed (immature or mature)
  • What bone
    ○ Anatomical structures on the bone
  • Normal or abnormal bone
  • Aggressive vs non-aggressive
  • Ranked list likely differential diagnosis
  • Plan
78
Q

Radiographic technique what is involved for musculoskeletal

A
  • Immobilized patient
  • Consistent positioning
  • Orthogonal projections (minimum)
  • Collimate to region of
  • Ensure marker is included
  • Grid may be required (>10cm) -> to reduce scatter
  • High contrast imaging -> want long exposure time so immobilisation important
  • Sharpening algorithm
79
Q

Age-related differences skeletal mature vs immature what occurs for radiograph and what looks like physis

A

Skeletal Mature vs Immature - has the physis closed
- Physeal closure times(tables)
○ Dog -> generally 3-6 months
- Are other growth plates open on same leg
- Compare to contralateral leg
Concerns - what looks like physis
- Salter Harris Fractures
- Avulsion fractures
- Delayed closures
- Physitis - horse and ruminants more commonly

80
Q

What are some basic bone changes on radiogrpahs and 2 main types of pathology

A

Bone Change
- Osteoclasts: dissolve bone
- Osteoblasts: make bone
- Osteocytes: maintain bone
- Bone Modelling: Increased bone volume
- Bone Remodelling: No change in bone volume but a balance of osteoclasts and osteoblasts activity
Pathology
- “Remove” bone: lysis, osteopaenia, osteoperosis
- “Produce” bone: osteosclerosis, periosteal new bone

81
Q

What is the ABCDS approach to viewing musculoskeletal x-rays

A

• Alignment/Apposition
• Bone
○ Breaks, periosteal surface, cortex, endosteal surface, medullary cavity
• Cartilage
○ Joint space - movement of fat pad, joint width, mineralisation, periarticular margins, subchondral bone
• Device (orthopaedic)
○ Osteolysis, ostroproduction, device movement
• Soft Tissue
○ Swelling, atrophy

82
Q

What are the 4 steps in the systematic approach to musculoskeletal radiographs

A

1) ABCDS approach to viewing musculoskeletal x-rays
2) describe abnormal finding
3) interpretation - normal vs abnormal
4) list differential list

83
Q

What are the 4 important things to describe with an abnormal musculoskeletal radiograph

A
○ Location
§ Which bone of skeleton e.g. humerus
§ Joint associated, epiphysis, physis, metaphysis, diaphysis
§ Subchondral bone, periosteum, cortex, endosteum, medullary
○ Number
§ Monostotic, polyostotic (multiple bones involved) or generalised
§ Monoarthropathy, polyarthropathy
○ Size, shape, contours, proportions
○ Opacity
§ Changes to architecture
§ Changes to bone density and structure
§ Osteopenia, osteopetrosis
§ Osteolysis pattern
§ Periosteal new bone formation pattern
§ Sclerosis
84
Q

What makes an aggressive vs non-aggressive lesion

A

○ Characteristics
§ Cortical Integrity - is there loss of cortical bone
§ Pattern/Transition of Lysis - well defined boarders more chronic
§ Pattern of New Periosteal Bone Formation
○ Presence of ANY ONE of these “aggressive” finding are sufficient to classify as aggressive
○ Helps formulate and prioritise the differential list and guide future treatment and prognostics

85
Q

Pattern of bone lysis and transition zone what type of bone change, how do the margins appear and the 3 main types

A
AGRESSIVE bone changes
- The more aggressive the lesion the harder it is to contain
- How do the margins appear
○ Distinct vs Indistinct
○ Long or short transition zone
- Main Terminology
○ Geographic
○ Moth-eaten
○ Permeative -> MOST AGGRESSIVE 
§ Unable to determine where bone lysis begins and ends
86
Q

Periosteal new bone (PNB) formation what type of bone change, appearance

A

AGGRESSIVE bone changes
- The appearance of PNB gives information on the activity of the lesion
- Aggressive Lesion
○ More likely to have active PNB
- Less Aggressive/Non-aggressive
○ More likely to have slow, organised, less active PNB
- Visual Scales of PNB findings

87
Q

What are the 2 main differentials for aggressive bone diseases and the main ones for non-aggressive bone disease

A
  1. Neoplasia - more likely in older animals
    - Primary Bone Tumour
    » Osteosarcoma
    » Chrondosarcoma
    » Fibrosarcoma
    » Haemangiosarcoma
    - Metastatic Bone Tumour
  2. Osteomyelitis - more likely in younger animals
    - Bacterial
    - Fungal
    - (Protozoal)
    Non-Aggressive Bone Disease
    - Examples
    ○ Bone cysts
    ○ Fractures
    ○ Developmental diseases
    ○ Metabolic bone diseases
88
Q

What are the 3 main ways to prioritising differential ist

A
  1. Signalment
  2. Lesion Location(s)
  3. Aggressive or non-aggressive
  4. Pattern of Bone Lysis and transition zone
  5. Presence of Cortical Lysis
  6. Pattern of Periosteal New Bone Formation
  7. Rate of Progression
    § An aggressive lesion tends to progressive rapidly
    § Can change appearance over a week (7-10days)
89
Q

General locations for lesions in 1) primary bone tumours, 2) metastatic bone tumours, 3) bone infection 4) benign lesions

A

1) Primary Bone Tumours
○ Favour the metaphysis of long bones
○ Usually monostotic
○ “Away from the Elbow, Towards the Knee”
2) Metastatic Bone Tumours
○ Usually in the diaphysis and polyostotic
3) Bone Infection
○ Haematogenous favours metaphysis and usually polyostotic
○ Inoculation can be anywhere
4) Benign Lesions
○ Are usually subchondral

90
Q

Osteoarthritis radiographic findings what are the 6 main ones and define osteophyte and enthesophy

A
  1. • Synovial thickening/Joint Effusion
  2. • Osteophyte formation
  3. • Enthesophyte formation
  4. • Subchondral bone sclerosis
  5. • Subchondral bone cyst formation
  6. • Narrowing of the joint space
    • Osteophyte
    - Periosteal new bone formation that develop at the periarticular margin
    • Enthesophyte
    - Periosteal new bone formation that occurs at a point of traction.
    - That is at ligament, tendons or joint capsule attachments
91
Q

hip and elbow dysplasia what breeds common in, pathogenesis and cause te

A
  • Labrador Retriever, Golden Retriever, German Shepherd Dog, Bernese Mountain Dog, Rottweiler etc
    Pathogenesis
  • Laxity (genetics and environments) or poor fitting joint -> subluxation -> osteoarthritis
    ○ Poor joint congruence causes osteoarthritis which can have devastating effects
    Aetiology - multifactorial
  • Genetics, breed, familial groups
  • High plane of nutrition as a puppy
  • Trauma
  • Poor muscle development
  • Asynchronous growth of radius and ulna
  • Excessive exercise as a puppy
92
Q

what are the 2 ways to reduce the prevalence of hip and elbow dysplasia and what type of inheritance therefore how hard/easy to eliminate

A
  1. Identify affected individuals - RADIOGRAPHIC SCREENING PROGRAMS
  2. Remove them from breeding population - BREEDING DECISIONS
    Traits with polygenic inheritance and variable phenotypic expression, affected by environmental factors, are more difficult to control
    - Pick a cut-off point and not breed from one way
    - Will shift the frequency curve to an increase in frequency the way you are breeding - NOT ELIMINATE
93
Q

List the 10 main features of a radiogrpahic screening program

A

1) disease must be heritable -
If HI >0.2 severity/frequency of trait may be influenced by selective breeding
2) radiiogrpahic trait must correlate with presence of disease
3) radiogrpahic trait must be heritbale
4) radiographic trait can be repeatbly scores
5) scoring can take place at a young age
6) a database is kept to record findings and animal pedigree
7) mandatory submission of radiographs - IMPORTANT
8) widespread uptake of the screening program
9) screening program must be affortable and widely accessible - lots of vets/technicians
10) breeders must use the information to select breeding animals - what we have little control over

94
Q

what makes a radiographic trait can be repeatable scored and which measures make better repeatability

A

(A) Within the single observer
(B) Between observers
(C) Within the one animal, as the animal ages
- Better repeatability with OBJECTIVE measures rather than SUBJECTIVE scoring features
○ Limit the number of evaluators, well trained evaluators - IS DONE - NEED TO BE TRAINED

95
Q

mandatory submission of radiographs for screening program why important

A

○ Is crucial to integrity of the database
○ Prevents submission bias and avoids a false impression of improvement within the breed population
§ If take radiograph and know its screwed and want to save client money BUT results in bias - ENCOURAGE SCREENING PROGRAMS

96
Q

what is important to remember to ensure breeders must use the information to select breeding animals

A

○ If too stringent selection criteria applied:
§ Rapid progress in improving phenotype
§ Marked reduction in number of available breeding animals, narrow gene pool
○ If too lax criteria applied:
§ Progress will be slow to absent
§ Increased number of available breeding animals, larger gene pool

97
Q

what should we use to help breeding for selection programs

A
  • ESTIMATED BREEDING VALUES (EBVs)
    ○ estimate the breeding worth of the animal, based on the performance of the individual and close relatives
    ○ EBVs are 1.16 to 1.34 times more accurate than individual scores or both parental phenotypic scores
    ○ EBVs are not yet widely adopted
    ○ The use of ordinal EBVs may increase the rate of genetic improvement
98
Q

Medial coronoid process disease common lesion of and radiographic findings

A

The most common lesion of elbow dysplasia
- Radiographic findings:
○ abnormal contour / poor definition of MCP
○ +/- fragmentation of MCP (=FCP)
○ secondary OA
§ osteophyte formation at proximal margin of anconeal process - blunted
§ sclerosis at base of MCP - radiographic sign most strongly correlated with FCP
§ sclerosis of ulna trochlea
osteophyte formation on radial head, humeral condyle, and medial epicondyle

99
Q

Un-united anconeal process what lesion from and radiographic findings

A

Elbow dysplasia
- Radiographic findings:
○ Lucent line separating anconeal process from olecranon
○ severe secondary OA must take a flexed ML view - moves medial epicondyle out of the way
○ BEWARE: in animals < 6 months of age, medial epicondyle has an open growth plate that may mimic UAP in a non-flexed mediolateral view! - THEREFORE NEED TO FLEX ELBOW FULLY

100
Q

Osteochondrosis of the humeral trochlea what lesion from and radiographic findings

A

Elbow dysplasia
- Best seen on the CC projection but secondary OA may be seen on ML view
- Radiographic findings:
○ concave subchondral lucency or flattening on medial aspect of humeral trochlea (condyle)
○ +/- subchondral sclerosis
○ +/- fragmentation (OCD)
○ secondary OA

101
Q

Subtle elbow incongruity what lesion from and radiographic findings

A

Elbow dysplasia
- Best seen on a well-positioned, neutral ML projection - mimic dog standing
- Radiographic findings:
○ ulna trochlea may be wide & malformed
○ uneven elbow joint space width
○ ‘step’ between articular surface of radius and ulna
○ Subtle incongruity not seen on radiographs - elbow CT or arthroscopy for diagnosis