Cranial Cruciate Rupture Flashcards by Chloe Tredinnick

What occurs to cause acute rupture? (2)

Hyperextension
Excessive tibial rotation

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With acute rupture; what force exceeds breaking strength of the ligament?

Force of the cranial tibial thrust

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What is found on CE with acute rupture? (4)

Non/partial weight bear
Pain
Joint effusion
Joint instability

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What is the most common cause of pelvic limb lameness?

Degenerative cr cruciate ligament dx

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What is seen on histo analysis of chronic cruciate ligament dx? (2)

Loss and metaplasia of the ligamentocytes
Failure to maintain collagen fibres.

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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

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Cruciate dx - sex?

Female

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Cruciate dx - neutering status?

Neutered

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What are the 2 places a ligament can avulse?

Femoral origin
Tibial insertion

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Which location is ligament avulsion more common?

Tibial insertion

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What causes ligament avulsion in the skeletally immature?

Acute overload (e.g. after a fall)

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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.

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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.

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What surgical technique to reduce the tibial plateau slop in young dogs can be considered

proximal tibial epiphysiodesis

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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.

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Rupture of the caudolateral band alone does not cause instability - why?

The intact craniomedial band is taut in both flexion and extension.

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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.

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What does the cranial drawer test screen for?

Passive femoropatellar instability in the stifle

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If an isolated injury to the craniomedial part of the cranial cruciate ligament occurs, when is the stifle unstable?

Flexion

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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

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During cranial drawer test - is the femur or tibia held stable (whilst cranial force applied to other) ?

Femur

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What position should the stifle be in for the cranial drawer test?

Extension and flexion

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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.

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What does the tibial compression test mimic and assess?

Mimics loading of the stifle
Assess cranial tibial thrust

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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

What category is the following (stifle surgical repair): Tight rope

Extracapsular

What category is the following (stifle surgical repair): Fibular head transposition

Extracapsular

What category is the following (stifle surgical repair): Cranial closing wedge osteotomy

Corrective osteotomy

What category is the following (stifle surgical repair): Tripel tibial osteotomy

Corrective osteotomy

What category is the following (stifle surgical repair): Cora based levelling osteotomy

Corrective osteotomy

What category is the following (stifle surgical repair): Tibial tuberosity advancement

Corrective osteotomy

What category is the following (stifle surgical repair): Allograft

Intracapsular

What category is the following (stifle surgical repair): Fascial strip

Intracapsular

Define Intracapsular reconstruction technique

involve passing tissue through the joint using the “over the top” method or passing the tissue through predrilled holes in the femur or tibia or both

Advantage of Intracapsular reconstruction technique

mimic the original position of the original cranial cruciate ligament

Disadvantage of Intracapsular reconstruction technique (2)

invasiveness tendency of the graft to stretch or fail.

When suturing the proximal 2/3 pf the joint capsule with lateral fabello tibial suture. What care must be taken NOT to suture?

Fascia lata

Where is the hole created which will allow the placement of an isometric fabello tibial suture?

Several millimetres caudal and proximal to tibial attachment of patella ligament

What of the lateral fascia may continue to improve stifle stability?

Imbrication

When comparing peak vertical force following lateral suture placement to that following TPLO for the treatment of CCLR which statements is correct? A) Peak vertical force was greater at walk and trot at 12 months following TPLO surgery than following lateral suture surgery. B) Peak vertical force was greater at walk but not trot at 12 months following lateral suture than following TPLO surgery. C) Peak vertical force was greater at walk but not trot at 12 months following TPLO surgery than following lateral suture surgery. D) There was no difference between peak vertical force at walk and trot between groups at 12 months following surgery.

A) Peak vertical force was greater at walk and trot at 12 months following TPLO surgery than following lateral suture surgery.

Lateral fabello-tibial suture: Where is the skin incision made?

Make a lateral curved parapatellar incision from the tibial tuberosity extending proximally past the patella an equal distance.

Lateral fabello-tibial suture: Where is the fascia lata incised? Where is the incision extended to?

Along the cranial edge of the biceps femoris muscle. Distally into the lateral fascia of the stifle.

Lateral fabello-tibial suture: What 3 things are dose during the mini lateral para patella arthrotomy?

Resect remnants of the cranial cruciate ligaments Inspect the menisci and remove any damaged portions Close the joint capsule.

Lateral fabello-tibial suture: Following the lateral para patella mini arthrotomy. What 2 anatomical landmarks are identified?

Identify the lateral fabella and fabello-femoral ligament (=tendon of origin of the gastrocnemius muscle).

Lateral fabello-tibial suture: What strength of line for 10-15kg dog?

50lb

Lateral fabello-tibial suture: What strength of line for a 15-20kg dog?

80lb

Lateral fabello-tibial suture: What strength of line for a 20-40 kg dog?

100lb

Lateral fabello-tibial suture: What strength of line for a 40kg + dog?

100lb x 2

Lateral fabello-tibial suture: where is the suture initially passed?

Behind or through fibrous tissue

Lateral fabello-tibial suture: Where is the the hole drilled?

Drill a hole in the proximo-cranial tibia: - As proximal and cranial as possible - Just caudal to the insertion of the patellar ligament.

Lateral fabello-tibial suture: Where is the top strand passed? then where? Then what happens with the suture?

Just caudal to the distal patellar ligament from lateral to medial. Pass the suture back through bone tunnel from medial to lateral. Pass one free end of the suture through the crimp and the other end through the crimp in the opposite direction.

Lateral fabello-tibial suture: What is the aim of the suture placement? (2)

Eliminate cranial drawer Maintain full ROM

Lateral fabello-tibial suture: Where is the crimp placed?

Middle both ends - 1mm from edge

Lateral fabello-tibial suture: Where should the crimp sit?

Cranial tibial muscle

Osteotomies do not eliminate passive instability - what does this mean for post op CE?

Cranial drawer present

TPLO - what shape osteotomy?and where?

Crescent in the proximal tibia

The TPLO involves making a crescent shaped osteotomy in the proximal tibia with rotation of the A) fragment to level the B) plateau.

A) proximal B) tibial

What tibial plataeu angles neutralizes the cranial tibial subluxation according to biomechanical studies?

6.5 degrees

What approach is used for a TPLO?

A standard medial approach to stifle and proximal tibia is performed.

With a TPLO; what occurs after the intra articular structures are inspected? (2)

CCL debridement Partial meniscectomy (IF required

During a TPLO what are the advantages of applying a jig?

Improved limb alignment during osteotomy Stabilisation of tibial plateau segment in 1 plane during rotation

During a TPLO, what is the osteotomy carried out with and where?

Oscillating biradial saw blade Parallel to jig pins

TPLO: Insert a K-wire/Steinmann pin into the A) bone fragment (or grip with pointed fragment forceps) and rotate the proximal bone fragment according to B)

A) proximal B) the predetermined amount based on preoperative tibial plateau slope.

During a TPLO how is The tibial plateau is secured in the rotated position?

Inserting K wire from the tibial tuberosity

How do you finally stabilise the TPLO

Plate + screws

TTA an angle of 90 degrees is achieved - what is this angle?

the aim of advancing the tibial tuberosity such that a patellar tendon angle (PTA angle between the patellar tendon (ligament) and tibial plateau slope)

How was TTA determined?

The theory was based on a human study showing that either a cranial or caudal femorotibial shear force was present within the knee dependent on the degree of knee flexion.

TTA: the PTA angle of 90 degrees. would neutralise what forces? and what has it been termed?

Cranial and caudal shear forces Termed - cross over point

What can be done during a TTA to Stabilise cranial cruciate ligament deficient stifle and a luxating patella at the same time?

The tibial tuberosity can be transposed a few millimetres medial or lateral at the same time tibial tuberosity advancement is carried out

What is a TTO a combination of? (2)

Closing wedge ostectomy and tibial tuberosity advancement

TTO involves precise preoperative planning to achieve accurate correction of the A) angle without excessively altering the B)

A) Patellar tendon B) Tibial plateau angle

The CBLO is a unique, more recently developed, procedure which attempts to combine the advantages of (2)

- TPLO - TTA

Previous theory with TTA: What is present in the cranial cruciate ligament deficient stifle and so it was hypothesised that TTA would dynamically stabilise the canine stifle.

Cranial tibial subluxation

CBLO: The osteotomy is centred on the A) which achieves alignment of the B) (2)

A) CORA B) proximal anatomic axis and distal anatomic axis

What is the effect of a TPLO on the proximal anatomic axis, what happens 2ry to this?

A) Caudal shift B) Tranlsation

Acocym: CBLO

Cora Based Levelling Osteotomy

What is the outcome difference between CCWO and TPLO?

No difference

Outcome study differences between TTA and TPLO?

Although 2 recent studies have revealed a minor improvement with TPLO (previous - no difference)

Generic surgical complications? (5)

- SSI - Septic arthritis - Implant infection - Implant infection - Late meniscal injury

Fibular nerve injury is associated with what surgical approach?

Intra articular

Suture failure is a complication associated with what surgical approach?

Extra articular

Hemorrhage is a complication associated with what surgical approach?

Tibial osteotomy

Complications specific to intra articular techniques (3)

Fibular nerve injury Caudal cruciate ligament injury Graft failure

Complications specific to extra articular techniques (2)

Suture failure Fibular nerve injury

Complications specific to Tibial osteotomy techniques (6)

Haemorrhage Fractures (Tibia, tibial tuberosity, patella, fibula) Osteomyelitis Delayed union, non-union, mal-union Patellar ligament injury Intra-articular screw placement.

What is the cause of Cr cruciate ligament rupture in cats? (2)

- Trauma - Ligament degeneration

When should surgery be considered in cats? (5)

- More rapid recovery - Obese - young _ Active - when non surgery fails

Benefits of surgery over medical management in cats?

More rapid recovery

Which technique "type" may result in better outcomes in obese cats and cats with chronic degenerative changes, however, their superiority have not been demonstrated.

Tibial osteotomy

Define Extracapsular reconstruction techniques

involve placement of sutures outside the joint or redirection of the lateral collateral ligament.