Cruciate disease

Question 1

3 biomechanical functions of cranial cruciate ligament

Answer 1

To limit cranial translation of the tibia with reference to the femur

To limit hyperextension of the stifle

To limit internal rotation of the tibia with respect to the femur

Question 2

Anatomy of the cranial cruciate ligament

Answer 2

The cranial cruciate ligament originates from the caudomedial aspect of the lateral femoral condyle

Courses in a craniomedial direction to insert on the cranial intercondyloid area of the tibia.

Cranial and caudal cruciate ligaments spiral around one another as they course distally

Question 3

Anatomy the caudal cruciate liagment

Answer 3

arises from the lateral surface of the medial femoral condyle and passes caudodistally to insert on the lateral aspect of the popliteal notch of the tibia.

Cranial and caudal cruciate ligaments spiral around one another as they course distally

Question 4

Three presentations of cranial cruciate ligament failure

Answer 4

Major trauma

Degeneration of the CCL with age

Ruptures in young, large breed dogs

Question 5

Meniscus of the stifle - function

Answer 5

Load transmission and energy absorption

Rotational and varus-valgus stability

Lubrication

Allows joint congruity

Question 6

Meniscus of the stifle - anatomy

Answer 6

held in place by ligaments and soft tissue attachments

cranial and caudal meniscal horns are firmly attached to bone via the ligaments

medial meniscus is firmly attached to the medial collateral ligament and the joint capsule via the coronary ligament, but the lateral meniscus lacks these attachments – important implications

Question 7

Cranial cruciate ligament disease in the dog

Answer 7

Degenerative condition

Acute ruptures of normal ligament are uncommon

May only have a partial tear (stable joint but painful)

Osteoarthritis is often already present

Often a bilateral condition

Can affect young adults (usually large breeds)

Question 8

Which is the most common cause of cranial cruciate ligament failure in dogs?

Answer 8

Degeneration of the CCL with age

Question 9

Signalment of CCL disease in the dog

Answer 9

Breeds: Rottweilers, Chows, WHWTs, and labradors

Age: middle aged

Sex: females slightly overrepresented

Weight: overweight

Question 10

Presenting signs of CLL disease in dogs

Answer 10

Pelvic limb lameness

Initially improve with rest and NASIDs

Lameness returns with exercise

Difficulty sitting/rising

Partially weight bearing at standing

Question 11

Differential diagnoses for pelvic limb lameness

Answer 11

Cranial cruciate ligament rupture

Collateral ligament injury

Patellar luxation (medial or lateral)

Osteochondritis dissecans (OCD)

Neoplasia

Infection

Osteoarthritis

Polyarthritis

Caudal cruciate ligament rupture

Question 12

Diagnosis of CCL disease

Answer 12

Gait analysis

Physical examination
- Cranial drawer
- Tibial compression test (tibial thrust)

Radiographic investigation

Question 13

Gait analysis of CCL

Answer 13

Pelvic limb lameness

May be acute onset or chronic variable lameness

May have stiffness, reluctance to jump, and reduced exercise tolerance

Question 14

Physical examination for CLL failure

Answer 14

Standing: comparison of two limbs (muscle atrophy)

Firm medial thickening of stifle

Effusion

Stifle painful on extension

Pathognomic instability (unless partial tear where there may not be instability)

Cranial drawer and tibial thrust

Question 15

Radiographic investigation of CLL disease

Answer 15

Mediolateral and caudocranial views of both stifles

Joint effusion (reduction in size of infrapatellar fat pad)

Secondary arthritic changes

Rarely avulsion fractures may be seen

Question 16

Meniscal injury - which is more frequent

Answer 16

Medial meniscal injury more common than lateral

Question 17

Meniscal injury - History and presentation

Answer 17

Chronic history of lameness

Sudden deterioration

More lame than your average cruciate

Owners sometimes report a clicking or a popping sound

Large stifle effusion

Can occur AFTER surgical stabilisation of the stifle

Question 18

Types of meniscal injury

Answer 18

bucket handle tears, detachment of the caudal horn and fibrillation.

Question 19

Treatment of meniscal injury

Answer 19

Crushed or split meniscal tissue should be resected as it is a source of significant discomfort,

The damaged meniscal tissue should be carefully excised retaining as much undamaged meniscal tissue as possible.

Question 20

Prognosis of meniscal injury

Answer 20

Dogs with meniscal tears have a worse prognosis than those without - they are more prone to wear of the articular cartilage and development of DJD and post cruciate stiffness/lameness

Question 21

Partial cranial cruciate ligament injuries

Answer 21

Common

Clinical signs similar to complete ruptures (thickened and effused stifle)

Tibial thrust and cranial draw may be negative

Surgical exploration may be needed to confirm the diagnosis

Question 22

Conservative treatment for CCL disease

Answer 22

Very strict exercise reduction for 6-8 weeks

Further 6 weeks gradually increasing controlled exercise

Weight control

If meniscal injury surgery is needed

Larger dogs will not do well with conservative management

OA will progress regardless but may be slowed by surgical intervention

Question 23

Two types of surgical intervention for CCL injuries

Answer 23

Attempts to stabilise the joint by constraining the tibial thrust instability

Osteotomy techniques that alter the biomechanics of the stifle so that the CCL is no longer needed for joint stability

Question 24

Attempts to stabilise the joint by constraining the tibial thrust instability

Answer 24

Modified over the top facial graft

Lateral fabello-tibial retinacular suture

Question 25

Modified over the top facial graft

Answer 25

use of autogenous fascia lata +/- a portion of the patellar ligament to replicate the CCL

Limitations
- strength of attachment to the femur
- initial weakness of the graft

Can have good outcomes

Question 26

Lateral fabello-tibial retinacular suture

Answer 26

Strong, permanent suture placed around lateral fabella, runs over lateral aspect of the stifle, through a drill tunnel in the proximal tibia

Limits cranial translation and internal rotation of tibia

Increased risk of infection due to permanent suture

Commonly the suture either stretches, breaks, or pulls away from its attachment

Question 27

Osteotomy techniques

Answer 27

Tibial plateau levelling osteotomy (TPLO)

Tibial tuberosity advancement (TTA)

Cranial closing wedge osteotomy

Triple tibial osteotomy (TTO)

Question 28

TPLO

Answer 28

Tibial plateau levelling osteotomy

Most common surgery performed by orthopaedic surgeons

Outcomes are consistently reliable

Alters the tibial plateau angle

Eliminates the cranial tibial thrust force

Little or no effect on the cranial draw instability

Good for large breed dogs with bilateral disease, boisterous or obese dogs, and dogs with a steep tibial plateau angle

Question 29

TTA

Answer 29

Tibial tuberosity advancement

Involves moving the insertion of the patellar tendon more cranially to counter the cranial tibial thrust force

Question 30

Prognosis of CCL surgery

Answer 30

Good

90%+ of patients returning to soundness

OA will progress in most patients despite surgical stabilisation

Question 31

Post operative care for CLL surgery

Answer 31

Strict confinement and minimal exercise for 4-6 weeks post op

Osteotomies should be radiographed arounf 6-8 weeks after surgery

Exercise can be gradually increased over 6 weeks

Return to off lead activity by 12 weeks

Question 32

Caudal cruciate ligament injury

Answer 32

Rarely ruptures in isolation

Usually in combination with other ligaments when the stifle is dislocated

Diagnosis by detection of a caudal draw sign

Surgery should not be necessary - conservative treatment/hydrotherapy