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