Cranial Cruciate Rupture Flashcards
What occurs to cause acute rupture? (2)
Hyperextension
Excessive tibial rotation
With acute rupture; what force exceeds breaking strength of the ligament?
Force of the cranial tibial thrust
What is found on CE with acute rupture? (4)
Non/partial weight bear
Pain
Joint effusion
Joint instability
What is the most common cause of pelvic limb lameness?
Degenerative cr cruciate ligament dx
What is seen on histo analysis of chronic cruciate ligament dx? (2)
Loss and metaplasia of the ligamentocytes
Failure to maintain collagen fibres.
Which of the following factors do you think may contribute to the chronic progressive degeneration of the cranial cruciate ligament?
Abnormal conformation
Gait
Increased tibial plateau angle
Decreased tibial plateau angle
Obesity
Lack of fitness
Breed
Being neutered
Being female
Being male
Being entire
Abnormal conformation
Correctly checked
Gait
Correctly checked
Increased tibial plateau angle
Obesity
Correctly checked
Lack of fitness
Correctly checked
Breed
Correctly checked
Being neutered
Incorrectly unchecked
Being female
Cruciate dx - sex?
Female
Cruciate dx - neutering status?
Neutered
What are the 2 places a ligament can avulse?
Femoral origin
Tibial insertion
Which location is ligament avulsion more common?
Tibial insertion
What causes ligament avulsion in the skeletally immature?
Acute overload (e.g. after a fall)
If there is a large bone avulsion with ligament dx, what is the repair option?
Primary repair with reduction of the bone fragment and stabilisation with wire, K-wires or a screw can be successful.
What is the treatment for an avulsion if the fragment is too small to accept implant? (if skeletally immature)
A rehabilitation programme (controlled but increasing exercise, physiotherapy and NSAIDs as required) is continued until skeletal maturity at which point surgery (e.g. osteotomy) can be considered if the dog remains lame.
What surgical technique to reduce the tibial plateau slop in young dogs can be considered
proximal tibial epiphysiodesis
Common cruciate dx clinical findings? (7)
Stifle pain (on flexion and extension of the stifle).
A click can be felt in some cases on extension/flexion (when stifle is flexed and extended).
Quadriceps muscle atrophy.
Femorotibial instability:
Periarticular fibrosis (felt as amedial buttress) is caused by osteophyte formation along the trochlear ridges and fibrous tissue formation along the medial condyle and proximal tibia in an attempt to stabilise the joint.
Joint effusion may be palpable adjacent to the patellar tendon.
Patients tend to sit with affected leg projecting out.
Rupture of the caudolateral band alone does not cause instability - why?
The intact craniomedial band is taut in both flexion and extension.
If an isolated injury to the craniomedial part of the cranial cruciate ligament occurs, when is the stifle stable and why?
extension because the caudolateral part is taut in extension but lax during flexion.
What does the cranial drawer test screen for?
Passive femoropatellar instability in the stifle
If an isolated injury to the craniomedial part of the cranial cruciate ligament occurs, when is the stifle unstable?
Flexion
Cranial drawer test:
The index finger of one hand is placed on the A)
and the thumb of that hand is placed on the lateral B)
The index finger of the other hand is placed on the C) and the thumb placed on the head of the D)
A) Patella
B) Fabella
C) Tibial tuberosity
D) Fibula
During cranial drawer test - is the femur or tibia held stable (whilst cranial force applied to other) ?
Femur
What position should the stifle be in for the cranial drawer test?
Extension and flexion
As puppies have a normal degree of laxity in the cruciate - how can a cranial drawer test be interpreted?
In puppies with normal ligaments, there is a sudden “thud” or “end” of cranial or caudal movement, a definite end point, whereas with diseased or ruptured ligaments, the end point is soft with no sudden stop.
What does the tibial compression test mimic and assess?
Mimics loading of the stifle
Assess cranial tibial thrust
Tibial compression test:
One hand grasps the distal A)
as the index finger runs along the B) to the tibial tuberosity and maintains the stifle in slight C)
A) Femur
B) Patella ligament
C) flexion
Define a positive tibial compression test
If the tibial tuberosity is felt to subluxate cranially
True or false:
Tibial compression test is more painful
FALSE - The tibial compression test may cause less pain than the cranial drawer test
What is the The tibial compression test less sensitive at detecting?
Partial tears
What are the 2ry radiographic signs with cruciate rupture? (4)
Joint effusion
Osteo- and enthesophyte formation
Subchondral sclerosis
Cranial tibial subluxation
With cruciate dx. Where do osteo/enthesophytes form? (4)
Tibial condyle
Trochlear ridge
Distal pole of the patella
Around the fabellae
How is joint effusion seen on cruciate dx xrays? (2)
Compression of the infrapatellar fat pad
Extension of the caudal joint capsule
What would synovial fluid analysis rule out?
Joint sepsis
What is joint fluid analysis of cruciate dx comparable with?
osteoarthritis (i.e. white blood cell counts less than 5 x 109l).
When performing synoviocentesis of the stifle, should fluid be obtained from the femoropatellar joint or the femorotibial joint?
Femoropatellar joint
When performing synoviocentesis of the stifle it is easier to obtain fluid from the femoropatellar joint than the femorotibial joint. Why?
Infrapatella fat pad
What other imaging can be used to diagnose both cranial cruciate ligament disease and meniscal tears but these are unnecessary in most cases? (4)
Stifle arthroscopy
CT arthrogram
MRI
Ultrasound
In patients <10kg. How long does it take for lameness to improve with those managed conservatively?
6 weeks (within)
What is the issue with conservative management in those >10kg? (2)
Does not allow return to preinjury activity without recurring lameness.
Shifting of weight to the uninjured leg might increase the risk of cranial cruciate ligament rupture in the contralateral stifle.
What are the 3 surgical technique categories?
Intracapsular
Extracapsular
Corrective osteotomy
What category is the following (stifle surgical repair):
Lateral fabello-tibial suture
Extracapsular reconstruction
What category is the following (stifle surgical repair):
Bone anchors
Extracapsular reconstruction
What category is the following (stifle surgical repair):
TPLO
Corrective osteotomy
What category is the following (stifle surgical repair):
Synthetic Graft
intracapsular reconstruction