LOCO SA Flashcards
What is a key differential for HL lameness in the dog?
cranial cruciate ligament disease
Is cranial cruciate ligament disease commonly seen in cats?
No it is rare!
What is this showing?
The cranial cruciate ligaments of the stifle- one is normal the other one has undergone degenerative weakening.
What are the 3 causes for cranial cruciate ligament rupture?
- traumatic avulsion
- traumatic rupture
- degenerative weakening
What is the most common cause of cranial cruciate ligament rupture?
degenerative weakening
What is the pathogenesis of cranial cruciate ligament degenerative weakening?
Complex!
involves conformation changes, abnormal biology including inflammation and apoptosis, and abnormal muscle and joint conformation
Cranial cruciate ligament rupture often goes hand in hand with damage to the…
meniscus
Which meniscus usually undergoes the most damage?
the medial meniscus
If there is meniscus damage, is it more painful when the stifle is in flexion or extension?
Extension
crushes the meniscus
The menisci convert compression into …
Tension (sexual tension?)
Where is the meniscal blood supply located/ distributed
Outer rim
What are the menisci? What are their poles?
2 C shaped fibrocartilage,
triangular with caudal and cranial poles
What ligaments do the menisci have?
The medial has:
- medial collateral
- meniscotibial
the lateral has:
- meniscofemoral
Is the onset of cranial cruciate ligament disease acute or chronic at presentation
Varies
can present itself acutely and can also be more insiduous
What is the positive sit test?
When the affected leg of a dog is out to the side (cranial cruciate)
not pathognomic
lumbosacral disease can sometimes look like..?
HL lameness
Dogs with cranial cruciate disease tend to not want to flex their stifles so instead they …?
circumduct their leg
What are the 2 stability tests we use to assess the stifle?
- the cranial draw
- the tibial thrust
Which is the most reliable stability test for assessing the stifle?
the cranial draw
Which is the most well tolerated stability stifle test?
the tibial thrust
Can you get false positives and false negatives with the cranial draw stability test?
Yes
false positive: if torsion twist
False negative: incorrect technique
Can you diagnose a cranial cruciate rupture with radiographs?
No, but you can see secondary signs!
- stifle effusion
- osteophytes
- distal displacement of the popliteal sesamoid bone
which radiographic views are important for assessing cranial cruciate ligament damage ?
orthogonal views (lateral and VD)
When aligning the stifle for radiographs which structures should you use as reference?
The fabellae
What are these?
These are osteophytes-
Radiographically this is what they look like
How do you treat cranial cruciate ligament rupture?
- you can start with 8 weeks of conservative treatment (rest and anti-inflammatories)
- if this does not work–> SURGERY
If you have meniscal injury and cruciate ligament rupture- what is the treatment?
Surgery
What is the ONLY role of surgery in cranial cruciate ligament?
To stabilise the joint
stop/reduce tibial thrust
(Surgery will not prevent OA)
Whenever surgery of the cranial crucial is being performed what must you MANDATORILY INSPECT?
the menisci
What are the 3 surgical techniques used for stabilising a cranial cruciate ligament rupture?
- intra-articular
-extra-articular - osteotomy techniques
Describe the intra-articular technique used for cruciate ligament rupture?
intra-articular graft through a bone tunnel
doesnt work well
What is this surgical technique?
Extra-articular
put a band around the joint to stabilise- the suture will snap off at 2 months, but by that time fibrous tissue should have been laid down around the joint.
What is the principle of surgical osteotomy techniques used for cruciate ligament rupture?
Flatten the tibial plateau
eliminate tibial thrust
What are the two osteotomy techniques used?
TPLO- tibial plateau levelling osteotomy
TTA - tibial tuberosity advancement
What is this surgical technique and what is it for?
TPLO
cranial cruciate rupture
What is this surgical technique?
TTA
What are the 2 common stifle problems seen in SA?
- Cranial crucial ligament rupture (due to degenerative disease)
- Patellar luxation
What is more common lateral or medial patellar luxations?
Medial patellar luxations
Patella luxation- is it congenital or developmental?
developmental
The patella is a sesamoid bone found in which muscle tendon?
the quadriceps muscle tendon
If the patella is not in the groove during development what happens?
the groove does not develop- it needs pressure
abnormal depth
abnormal alignment
image shows a flat surface instead of a groove
What is the pathophysiology of patellar luxation?
the quadriceps develop incorrectly–> uneven pressure on physis of bones—> bone deformities
Patellar luxations tend to occur in what type of dogs?
Small dogs
What is the typical lameness of patellar luxation?
INTERMITTENT
Do patellar luxations tend to have effusion?
minimal
If a dog has genu valgum - will the patella be medially or laterally luxated?
(gum so legs ‘stick’ together)
laterally
If a dog has genu varum - will the patella be medially or laterally luxated?
medially
if you push on patellar and there is pain ‘retropatellar pain’ this may suggest..
cartilage damage
A history of intermittent skipping should make you think of…
patellar luxation
patellar luxation grading: if a patella is in the groove at rest but can intermittently pop out- what grade?
Grade 1- not clinically important
patellar luxation grading: if a patella is NOT in the groove at rest and the patella can never be returned inside the patellar groove?
Grade 4- surgery required
patellar luxation grading: if a patella is in the groove at rest but can stay out of the patellar groove?
Grade 2- these vary from mild- to severe
patellar luxation grading: if a patella is NOT in the groove at rest but can still be returned to the groove?
Grade 3- persistently abnormal stifle joint- lameness can be SUBTLY surprisingly!
If patellar luxation is a high grade what type of X-rays do we do?
entire limb radiographs
This radiograph looks NORMAL- however it is showing a patellar luxation
patellar luxations can look normally radiographically
Which grades of patellar luxation generally require surgery?
Grade 3
Grade 4
(Grade 2- if severe)
What influences the prognosis with patellar luxations?
The grade
What influences the choice of surgery for correcting a patellar luxation?
- not just the grade
- evidence of pain
- Owner awareness that OA will NOT be prevented
- unilateral surgery in a bilateral disease
What are the treatment options for a dog with grade 1 or 2 patellar luxation, with no pain and no lameness but an instable patella?
physiotherapy
If a dog has grade 2 patellar luxation with weekly lameness (and retropatellar pain)- what would be the treatment?
surgery
What are the surgical treatment options for patellar luxations?
- trochleoplasty
- chondroplasty (rare)
- wedge resection
- block resection
What surgery is this
wedge resection to deepen the patellar groove
What surgery is this?
Block recession sulcoplasty
What technique is this?
trochleoplasty- terrible technique, rasp off the cartilage causing alot of OA-
other techniques are better
What is this surgery called?
Chondroplasty- need to do it if animal is less than 6months old
RARELY DONE
Following a wedge/block resection - you will almost always need to do what other surgery?
Most cases, the tendon is deviated so will need to be realigned with a TTT (tibial tuberosity transposition)
What is this?
TTT
Tibial tuberosity transposition
you transpose the tibial tuberosity to realign the femus with the tibia
Can you do a TTT in a skeletally immature patient?
May influence bone growth!
Best wait >10months
or do a two stage surgery
What are the broad categories of Arthritis?
In the immune mediated arthritis which category is most common, erosive or non erosive?
non- erosive
In IMPA, is one or several joints commonly affected?
multiple joints affected
If a patient presents with swollen joints and systemic signs what are the most likely causes of arthritis?
- Inflammatory causes:
1ry or secondary - Infectious
- (Neoplasia)
What infectious causes may lead to IMPA?
Ehrlichia, Heartworm , Leishmaniosis
What features may you see with IMPA on clinical exam?
- ligamentous laxity
- effusions
- swollen joints
- 35% lame
- MULTIPLE joints effected
How can we investigate polyarthropathy?
- arthrocentesis (most common)
- X rays (not very helpful)
- synovial biopsy
If we suspect IMPA what can we do to investigate?
- do an arthrocentesis to differentiate between septic and immune mediated
- X rays?
- synovial biopsy
- Look for underlying cause!! (bloods, PCR..)
Is lactate higher in Septic arthritis or Immune mediated arthritis?
Septic arthritis
How can you tell the difference between septic and immune mediated arthritis?
Do an arthrocentesis
- Septic typically has higher total protein ( >4%) Vs immune mediated has 2.5-3%)
- may have higher neutrophil count in septic athritis (> 90%) Vs (10-95%) in immune mediated
You take an arthrocentesis from a joint with arthritis- what is the left showing and the right showing ?
Left: high neutrophil count—> Inflammatory type
Right: high mononuclear cell count—> non- inflammatory
re radiographs useful for assessing non-erosive arthritis?
No- may see effusion…
Borrelia (lyme disease), Systemic Lupus Erythmatoid, and drug associated arthritis are all examples of erosive or non erosive immune mediated arthritis?
These are non - erosive
Erosive IMPA can look like… arthritis
septic arthritis
What does this represent?
a carpus with erosive arthritis
note the sclerosis and erosion present compared to this healthy carpus
What is the pathophysiology of erosive IMPA Vs non- erosive
Erosive : chronic synovitis–> granulation tissue—> collagenase and proteases lead to bone destruction
Non- erosive: immune hypersensitivity response type 3—> antibody and antigen deposits in the synovium—> chemotaxis for neutrophils and macrophages
Radiography: erosive vs non-erosive
non erosive–> effusion maybe?
erosive: sclerosis and erosion
What is more common erosive or non-erosive IMPA?
non-erosive
erosive accounts for 1% of PA
Why do we want to differentiate between erosive and non erosive disease?
erosive disease requires more aggressive treatment and has a worst prognosis
What is this?
Septic arthritis - affects LA and SA
What is the prognosis for IMPA type 1 (idiopathic)?
56% can be cured
18% on lifelong treatment
12% relapse
Causes for septic arthritis
- trauma (ie horses)
- hematogenous spread
- spread from local tissue
- iatrogenic Ie aseptic procedure
What is this showing?
osteochondritis dissecans
Problem with vasculature during endochondral ossification leads to a thickened area of bone
What is this showing?
Osteochondritis Dissecans- underrunning of necrotic tissue- flap of cartilage on top
What is this showing? Which breed does this typically affect?
Osteochondritis dissecans- note the flap!
LARGE DOGS
If you can’t see whether a shoulder or elbow joint has Osteochondrosis dissecans what can you do?
contrast arthrogram
What is this showing? Are they always this obvious?
Osteochrondrosis dissecans- not sometimes you cant see it radiographically- so you may need contrast
What is this showing? What type of dog does this typically affect?
Shoulder luxation
What is this test called?
The bicipital test
It is used to see whether the animal has bicipital disease-
Shoulder is flexed and the elbow is extended- if it can fully extend that means it has bicipital disease.
What is bicipital disease?
degeneration of the biceps tendon
Which letter represents the Medial coronoid process?
A
Elbow dysplasia is an umbrella term for ….. diseases
developmental
All elbow dysplasias lead to what other disease?
OA
What is the aetiopathogenesis of elbow dysplasia?
growth mismatch between radius and ulna- leading to radial ulnar incongruity
If during elbow development, the radius is too short, where will there be more pressure at the elbow joint?
At the MCP
If druign elbow development you have a long radius - where in the joint will there be most pressure?
the anconeal process
Why is elbow dysplasia a big problem in dogs?
- euthanasia in 41%
- bilateral in 60%
Where is the Medial coronoid process and where is the anconeal process on this picture?
What does this photo show?
Open physis:
- radius
- olecranon
(the humeral physis is not visible on this picture)
If the humerus is relatively too large at the humero ulnar joint- what do you call this dysplasia?
humero trochlear notch - humero ulnar confilct
Elbow dysplasia is frequently lateral or bilateral?
bilateral
How many views do you need to take for elbow dysplasia?
3:
1 cranio caudal
1 mediolateral flexed
1 mediolateral neutral
What is this?
elbow arthroscopy
Can you see the disease on this picture?
this is a diseased medial coronoid process
Is the medial coronoid easy to diagnose via radiography?
No, we diagnosise it by elimination- if no UAP or OCD then MCP!
What is this? Can you see the cartilage?
This is a CT- you cannot see cartilage on CT
What elbow dysplasia is this?
Ununited anconeal process
What is this showing? It is an elbow dysplasia
ununited anconeal process with CT and arthroscopy
How can you surgically treat an Ununited anconeal Process? (3)
1) remove the anconeal process (leads to OA)
2) osteotomy of the ulnar
3) or cut ulnar to relieve pressure and add a pin to allow the anconeal process to heal! (this is the best) see pic
How can you surgically treat an Ununited anconeal Process? (3)
1) remove the anconeal process (leads to OA)
2) osteotomy of the ulnar
3) or cut ulnar to relieve pressure and add a pin to allow the anconeal process to heal! (this is the best) see pic
What does this show?
OCD of the humerus
Is OCD of the humerus common?
uncommon
OCD in the dog commonly affects which joints?
- Elbow
- shoulder
(Stifle and tarsus)
What leads to MCP?
microfracture due to overload
What are these pictures showing?
CT scans of MCP
What is the best treatment for MCP?
arthroscopy >
arthrotomy and conservative treatment (omega 3, regularised exercise, weight control…)
All types of elbow dysplasias lead to …
OA!
Lameness may implicate which 2 systems
neurology
orhtopaedics
Locomotor conditions are characterised by 2 things
- lameness
- gait abnormality
Hip dysplasia is common in…
large breed dogs
What is the pathophysiology of hip dysplasia?
Born normal
then at 30 d–> hip laxity in joint
leads to pain–> inflammation—> bone remodelling—> OA
Does feeding/ body weight affect OA in hip dysplasia?
YES!!
Dogs with hip dysplasia usually present at what age?
- 6-7 months
- or older when they have OA
What are the key clinical findings on PE that point to hip dysplasia?
- PAIN when extending the hip or abducting the hip
-(muscle atrophy
- clunking)
If the dog is old, make sure not to confuse hip dysplasia with …
cranial crucial ligament disease
What leg position is needing for Xrays of hip dysplasia?
- VD extended
- lateral pelvis
Is this a good radiograph for assessing hip dysplasia?
YES
Is this a good radiograph for assessing hip dysplasia
no, pelvis is rotated , ilial wing larger on the right compared to the left side. Obturator foramen is bigger
Is this a good radiograph for assessing hip dysplasia?
No, pelvis is straight but femurs are not straight
What is the normal acetabular coverage of femoral head ?
50%
Can a dog with severe OA still have good hip function?
YES
treat the dog not the radiograph
Ortolani test is used to assess
hip dysplasia
push down into hip joint then abduct-> if clunks then hip dysplasia
Bardens Test assesses..
hip dysplasia
(if >0.5cm femur lift out of joint then hip dysplasia)
What is the first line treatment for dogs with hip dysplasia ( young and old)?
Conservative management:
1) short regular exercise
2) diet ‘keep lean’
3) hydro
4) Omega 3
5) NSAIDs
What prophylatic surgeries do we have for hip dysplasia if conservative management fails?
- pelvic osteotomy
- Juvenile pubic symphysodesis
What definitive surgeries do we have for hip dysplasia if conservative management fails?
arthroplasties:
Total hip replacement
Femoral head and neck excision
Why is screening for hip dysplasia problematic
- based on radiographic signs
(looking at primary disease and OA) so NOT CLINICALLY RELEVANT - does not measure laxity
- hip dysplasia is polygenetic (so a dog with good radiographic score may carry bad genes!)
What clinical findings may there be with a dog with Legg Calve Perthes?
- same as hip dysplasia:
pain on hip extension and abduction
muscle atrophy
What is the pathogenesis of Legg Calve Perthes?
How do you treat Legg Calve Perthes
SURGERY OBLIGATORY:
- FHNE
(THR)
What radiographic views may you use for Legg Calve Perthes?
VD frog leg
lateral
What is the most common hock problem?
Trauma
Casting tape is applied to which layer?
a light 2ndary layer
How many layers are involved in a bandage?
3
What is the primary layer of a bandage?
Allevy, Melolin
- covers and protects skin
- absorbs discharge
What is the second layer of a bandage?
- cotton wool or cast padding
- conforming gauze is wrapped around
What is the 2nd layer of a bandage for?
support, absortion and pressure
What is the 3rd layer of a bandage?
elastic gauze/ Vet wrap
allows consistent pressure to outer layers
If you put too little casting tape on what is the risk?
rubs and sores
If you put too much casting tape on what is the risk?
movement of bone fragments
delayed healing
What is this?
A Robert Jones bandage contains alot of cotton wool
Leave open if possible
What are the indications for a Robert Jones bandage?
- temporary immobilisation
- reduces swelling
- cotton wool loosens over time and stability is lost
What is this?
a splint used for bandage support
What is the difference between a Robert Jones and a Modified Robert Jones?
Modified Robert Jones uses cast padding instead of cotton wool
How many layers of cast padding are there in a Modified Robert Jones? On which layer is the splint applied?
- 3
- after the 2nd layer of cast padding
The Modified Robert Jones can offer temporary immobilisation IF it is…
SPLINTED
Should both the Robert Jones bandage and the Modified RJ be left open ended?
preferably yes
Casts can be ….
bivalve or one-piece
What are longer term immobilisation techniques?
- casts (bivalve or full)
- immobilisation devices : Schroeder Thomas Splint
Spica Splint
Why would be opt for a bivalve cast?
- fracture management
- allows easy inspection
Accurate application of a bivalve cast requires…
GA
For a cast should toes be in out out?
in
Which are the 4 forces acting on fractures? Which ones respond well to external co-aptation?
Bending
Rotation/ torsion
Shear/ compression
Distraction / Avulsion
Bending and torsion respond well
As distraction forces in a fracture do not response to external coaptation- what can we do instead?
sling
What are unsuitable fractures for coaptation?
- comminuted
- unstable spiral or oblique
What are suitable fractures for coaptation?
some simple oblique or spiral
simple transverse
paired bone- ulna or fibula intact
We need to immobilise a fracture….
above and below the fracture
External co-aptation is unsuitable for (3)
- fractures above the stifle and elbow
- articular fractures
- fractures involving growth plates
Consider reduction for a fracture is the is atleast …% overlap between fracture ends on both orthogonal views
50 %
Can you apply casts on distal radius and ulna?
No
Can you cast a sighthound?
no- too little soft tissue coverage
Can you cast a dystrophic dog or Obese dog?
No- bandages do not stay on
What is the ideal patient for casting and bandaging?
- juvenile with high healing potention
- atleast 50% coverage of both bone ends
- stable closed fracture
- one intact paired bone
If a dog has had a RTA and has a broken radius, what can you do?
- first apply bandage
- Make a cast after 2-3 days once swelling has gone done
In fracture management: …alignment is more important that… alignment
joint alignement> bone alignement
If you have a fracture in the radius you would need to cast from ..
above the elbow to the floor
Always cast a limb in a normal standing position and that allows normal…
weight bearing
Complications of external coaptation are common and include
- soft tissue injuries
- mal union
- non-union in toy breed antebrachium
- swelling (dont bandage to the tips!)
