Stifle

Question 1

Cranial cruciate ligament

Answer 1

Runs from medial aspect of lateral femoral condyle to craniomedial aspect of proximal tibia

Question 2

Caudal cruciate ligament

Answer 2

Inter condylar fossa of femur to caudal tibia

Question 3

What are the functions of the cruciate ligaments?

Answer 3

Prevent rotation and hyperextension of the stifle

Question 4

How can you usually differentiate stifle disease from hip disease?

Answer 4

Stifle disease - toe touching - won’t flex stifle

Hip disease - carry leg higher with stifle in flexion

Question 5

How can you perform a cranial drawer?

Answer 5

Test the leg in both flexion and extension
Index finger on patella
Other index finger on tibial all tuberosity
= cranial movement and instability in the stifle

Note - caudolateral band can produce a false negative with the leg in extension (taught)

Question 6

How can you perform a tibial thrust?

Answer 6

Hold stifle in extension
Flex the hock
Finger over the tibia tuberosity will be displaced cranially

Question 7

Where can you perform synoviocentesis in the stifle?

Answer 7

Lateral femoral-tibial compartment

Femoropatellar compartment - yields lots of fluid

Question 8

What are the two bands within the cranial cruciate ligament?

Answer 8

Craniomedial band - taught in both flexion and extension
= more commonly ruptured

Caudolateral band = only taught in extension

Question 9

What is the most common aetiology of cranial cruciate ligament rupture?

Answer 9

Degeneration and minor trauma

Labrador, terriers and bull mastiffs predisposed

Question 10

How does rupture of the cranial cruciate ligament present?

Answer 10

Acute or chronic onset hindlimb lameness
Leg carried flexed
Toe touching
Stifle effusion - loss of definition of the patellar ligament
Medial buttress (chronic thickening on medial stifle)
Positive tibial compression test (stifle in extension)
Positive cranial drawer (stifle in flexion and extension)

Question 11

How can you diagnose cranial cruciate ligament tears?

Answer 11

History
Clinical exam
Radiography - mediloateral and craniocaudal views

Question 12

When can conservative management of cranial cruciate ligament disease be attempted?

Answer 12

Patients under 15kg
Restricted exercise and analgesia for 6-8 weeks
85% have a satisfactory return to function

Question 13

When is surgical management of cranial cruciate ligament disease indicated?

Answer 13

Patients over 15kg

Or failed to respond to conservative management

Question 14

What surgical management options are available for CrCrLD?

Answer 14

Intra-capsular - over the top technique
Extra-capsular - lateral suture (lateral fabellotibial suture)
Peri-articular 
- tibial plateau level osteotomy (TPLO)
- tibial tuberosity advancement (TTA)

Question 15

What is the most common surgical method used for CrCrL disease?

Answer 15

Lateral fabellotibial suture

- nylon suture placed through a hole in the tibia and around the fabella

Question 16

What is the prognosis of surgeries for CrCrL disease?

Answer 16

All similar - around 80%

But animals that have had a TPLO seem to have a faster recovery

Question 17

What post-operative care is required follows stifle surgery?

Answer 17

Rest for 10 days
Gradually increased exercise after 10 days
Re-examine in 4-6w and again at 12w
Progress radiographs at 8w

Question 18

What are some complications that can occur following stifle surgeries?

Answer 18

Meniscal tears
- conservative management for 4-6 weeks
- surgical removal if persistent lameness 
Infection
Avulsion of osteotomy

Question 19

How does patella luxation usually present?

Answer 19

Young toy breed dogs
Due to a developmental malalignment of the quadriceps

Skipping lameness
Bunny hopping or crouching if bilateral

Able to luxate the patella on clinical exam

Question 20

How can you diagnose patellar luxation?

Answer 20

Radiography

History and clinical signs

Question 21

How can you treat patella luxation?

Answer 21

Grade 1
Restricted and controlled exercise
NSAIDS

Grade 2 and above requires surgical treatment

• reinforcement of lateral retinaculum
• release of the medial retinaculum
• deepening of the patella groove
• transposition of the tibial tuberosity

Question 22

How does stifle osteochondrosis often present?

Answer 22

Young male Labrador
Lameness from 5mo
Bilateral crouching gait
Stifle effusion and pain

Dx: radiography - medial and lateral femoral condyles

Tx: arthroscopy and debridement

Question 23

How does rupture of the collateral ligaments present?

Answer 23

Trauma +/- CrCrL involvement
Rx - widening of joint space on stressed view
Tx - parapatellar approach - primary repair of ligament

Question 24

How does multiple ligament injuries present and how can you treat them?

Answer 24

Working dogs

• CrCrL rupture
• meniscus tears
• collateral ligament tears

Tx - external fixation - transarticular pin

Question 25

How can you treat distal femoral fractures and proximal tibia fractures?

Answer 25

Cross pin
Ensure the pins do not cross at the fracture site

Proximal tibial fractures are common in terriers - may heal spontaneously

Question 26

How can you manage OA in the stifle?

Answer 26

Conservative
Stifle Arthrodesis
Total knee replacement

Question 27

What neoplasia is found in the stifle?

Answer 27

Synovial sarcoma

Distal femoral osteosarcoma