SA Hindlimb

Question 1

What are the d/dx for hip joint pathology?

Answer 1

• Hip Joint
• hip dysplasia
• Perthes disease
• osteoarthritis
• luxation
• fractures of proximal femur or pelvis
• muscle strains ( uncommon)

Question 2

What is canine hip dysplasia determined by?

Answer 2

animals genes

Question 3

At birth how do dogs genetically predisposed to hip dysplasia hips appear macroscopically?

Answer 3

Dogs genetically predisposed to HD have macroscopically normal hips at birth, but changes begin within a few weeks

Question 4

What promotes phenotypic expression of HD?

Answer 4

rapid growth and abundant food promote phenotypic expression of the HD

Question 5

Describe the bimodal age distribution of HD?

Answer 5

Bimodal age distribution of clinically affected dogs:

3-12 months: synovitis

2-12+ years: osteoarthritis

Question 6

Create a flow chart for the pathogenesis of hip dysplasia?

Answer 6

Question 7

What are the clinical signs of hip dyslpasia?

Answer 7

May be asymptomatic

May be non-specific: tires, doesn’t play, stiff on rising, reluctant to jump

Observe:

• stiffness on rising
• may stand shifting weight onto front legs
• bilateral or unilateral hindlimb lameness: may wiggle, cross legs or bunny hop

Palpate:

• hindquarter muscle atrophy, particularly gluteals

Manipulate hips:

• pain esp. on extension and abduction
• decreased range of motion or joint instability ± crepitus
• Ortolani sign

Question 8

What is joint laxity dependent on?

Answer 8

Hip Laxity Joint laxity is dependent upon:

• joint capsule thickness
• integrity of ligament of femoral head
• integrity of dorsal acetabular rim and muscle tension
• Surface tension in the synovial joint

Question 9

How can hip laxity be assessed?

Answer 9

• Barden ’ s Palpation (hip lift)
• Barlow’s Sign
• Ortolani Test (sedation / GA)

Question 10

What is the ortolani test?

Answer 10

• Pressing down on the femur see a subluxation of hip (angle of subluxation) then as you abduct the hip it should pop back in (Angel of reduction)
• Best indication of a degree of instability

A positive sign is a distinctive ‘clunk’ which can be heard and felt as the femoral head relocates anteriorly into the acetabulum

Question 11

How is radiography done for hip dysplasia?

Answer 11

• Ventrodorsal extended femur view - must be straight
• Lateral pelvis / LS junction ( ± flexed)
• Frog leg view Radiography (beware though can give a false impression that hips sit better than they do in reality in this view)

Question 12

How can we assess level of hip sub/luxation from radiographic images?

Answer 12

Want to look at dorsal acetabular rim: yellow squiggly line

The red dot on the femoral head should sit where the left red dot is in a non luxated hip.

Dorsal lateral acetabular ridge: White curve line looking at wear and tear on it

New bone: Yellow arrows. New bone seen in dorsal, ventral aspects of acetabulam and around the femoral head. A good indication joint is unhappy and under a degree of strain.

50% coverage of the femoral head is correct as seen in image

Question 13

What is the distraction index?

Answer 13

NOT appropriate for UK due to requirement to hold animal during radiography

0 = perfect congruity

0.3 -0.7 = abnormal

1 = complete luxation

Question 14

Describe conservative management for hip dysplasia?

Answer 14

Treatment Conservative management should always be tried first:

• weight control
• regular exercise to build muscle (especially the gluteals)
• physiotherapy and hydrotherapy
• strategic analgesia (5-7 days as and when needed)
• +/-nutraceuticals

The majority ( 76% ) of juvenile dogs with severe radiographic signs of hip dysplasia may be only mildly clinically affected in later life if they are properly managed: kept at optimal weight and regularly exercised

Question 15

What are the treatments for hip dysplasia?

Answer 15

Immature dog:

• pectineus myotomy / myectomy
• Triple/double pelvic osteotomy
• femoral neck lengthening
• DARthroplasty
• femoral head and neck excision
• pubic symphysiodesis

Mature dog:

• femoral head and neck excision
• total hip replacement

Question 16

When would a triple pelvic osteotomy be indicated in dogs?

Answer 16

Potential candidate would have:

• painful hip(s), non-responsive to analgesia
• unstable but reducible hips
• no / minimal remodelling or degenerative changes

so mainly immature dogs (5-10 months of age)

Question 17

What is the theory of the triple pelvic osteotomy?

Answer 17

Acetabular segment rotated laterally to capture femoral head –> stabilise hip –> clinical improvement and reduced DJD

Theoretically, degree of rotation determined from Ortolani angles (20, 30, 40 degree plates)

Bilateral surgery if appropriate -staged

Question 18

What is occuring here?

Answer 18

• Perthes disease –avascular necrosis of the femoral head
• Seen usually in small breed dogs, usually 3-13 months old
• Multifactorial aetiology (Manchester Terriers- highly heritable)

Question 19

What are the clinical signs of perthes disease?

Answer 19

Clinically:

• progressive lameness
• hip pain
• muscle atrophy
• reduced hip ROM
• crepitation

Usually unilateral –bilateral in 12-16.5% cases

Non-inflammatory aseptic necrosis of the femoral head and neck

Question 20

What are possible treatments for avascular necrosis of the femoral head?

Answer 20

Treatment –

• conservative (in his experience relatively unsuccessful)
• femoral head and neck excision
• total hip replacement

Question 21

What damage can happen to the stifle joint?

Answer 21

• Cranial cruciate ligament rupture
• caudal cruciate ligament rupture
• meniscal damage
• collateral / multiple ligament rupture
• OCD
• patellar luxation
• fracture of femur, tibia or patella

Question 22

What might you observe in a dog with cranial cruciate disease?

Answer 22

Observe:

• may sit avoiding stifle flexion
• often stiff to rise
• may stand with toes of opposite hind splayed
• may shift weight forwards onto front legs
• hip hike on affected side
• circumduct leg rather than flex stifle
• shortened anterior (forward) phase of swing

Question 24

On a clinical exam of a suspected cranial cruciate ligament rupture what might be seen?

Answer 24

Palpate:

• may be some muscle atrophy of affected leg(s), particularly of the quadriceps muscles
• may feel stifle effusion
• may feel medial buttress (see pic)

Manipulate:

• painful on extension
• unstable?

Question 25

List some of the causes of cranial cruciate ligament?

Answer 25

Question 26

How will cranial cruciate rupture appear on manipulation?

Answer 26

* Basics–range of motion, crepitus etc --\> painful stifle * Especially painful on hyperextension * Compare extent of internal rotation between both stifles * Cranial drawer motion is painful even in a normal joint --\> tense * Cranial tibial thrust

Question 27

What are the functional parts of the cruciate ligament?

Answer 27

Two functional parts: * small craniomedial band (CMB) taut in flexion and extension * larger caudolateral band (CLB) -CLB taut only in extension Most partial tears involve smaller CMB = drawer only in flexion

Question 28

A dog must be what to perform the cranial draw test?

Answer 28

Sedated or anaesthetised

Question 29

What can be seen in the yellow triangle?

Answer 29

Joint effusion shown by increased radio opacity

Question 30

Discuss conservative management of cranial cruciate ligament?

Answer 30

* Analgesia, exercise modification, physiotherapy * reportedly reasonable outcomes for dogs \< 17kgs * poor recovery if meniscal damage present (up to 48%) * degenerate conditions persist

Question 31

How often do partial tears progress to full ruptures of the cruciate ligament?

Answer 31

Partial tears in dogs consistently progress to complete tears within 1 year of onset of lameness 21-37% dogs reportedly rupture the CrCL in the other stifle within 2 years.

Question 32

Look at some arthroscopy of cruciate ligaments?

Answer 32

Question 33

What are the intra/extra-articular or combined methods of cruciate rupture repair?

Answer 33

Intra-/ extra-articular or combined methods: * stability afforded by prosthesis or tissue * some loss of joint range of motion e.g. over-the-top-technique (graft), tight-rope, extra- capsular suture.

Question 34

What are the plateau levelling methods for treating cruciate disease?

Answer 34

Plateau-levelling methods: * elimination of tibiofemoral shear force * stability only during weight-bearing * preserves joint range of motion e.g. Cranial Tibial Closing Wedge Osteotomy (**CWO**), Tibial Plateau Levelling Osteotomy (**TPLO**), Tibial Tuberosity Advancement (**TTA**) Surgical treatments

Question 35

What does the cruciate ligament do?

Answer 35

When an animal weight bares there is a tendency for tibia to move cranially that tendency is stopped by the cruciate ligament. When this fails the tibia can move forward. Thereby if you level the tibia it can non longer thrust forward and the cruciate lig is not require anymore.

Question 36

What are the complication rates of the different plateu levelling operations for cruciate disease?

Answer 36

Complication rates: TTA \> TPLO \>\> ECS

Question 37

When does a meniscal tear occur?

Answer 37

May be more painful / lame ±audible ‘ click ’ **Presence of meniscal tear at time of CrCL rupture:** * partial ruptures: 5-25% occurs * complete ruptures: reportedly up to 80% **Delayed / late meniscal injury after CrCL rupture:** * may be up to 14% * usually caudal horn of medial meniscus * caudal longitudinal tear (bucket-handle), and crushing of the caudal horn most common * inner 2/3 rds avascular, so healing is poor --\>requires (partial) meniscectomy

Question 38

Dicuss canine patella luxation?

Answer 38

* Common condition 2 sets suffer: small terriers and larger dogs * Caused by quadriceps / extensor mechanism mal-alignment * If patella not in groove during development, groove remains shallow * dogs may also have bony deformities of femur (varus) and tibia * usually congenital but occasionally traumatic

Question 39

What are the clinical signs of canine patella luxation?

Answer 39

* Commonest in small breed dogs: toys and terriers * Larger breeds: Labradors and Mastiffs * typically intermittent hopping lameness for few steps, then back to normal gait (often after extending leg caudally) * may be crepitus on manipulation, as cartilage on underside of patella and trochlear ridge becomes eburnated (worn away) * congenital medial patellar luxation commonest * occasionally lateral luxation seen in large breeds, or following trauma * occasionally concurrent cruciate ligament rupture

Question 40

How can patella luxation be graded?

Answer 40

Question 41

How can patella luxation be treated?

Answer 41

**Treatment** * imbrication of soft tissues lateral side of joint * soft tissue procedures not usually enough on own **Deepening of trochlea:** * Block recession * Wedge recession * Tibial tuberosity transposition (TTT) to realign extensor mechanism (not usual in cats) May require femoral or tibia osteotomies to straighten –refer! Not usually necessary in cats

Question 42

Draw an image of block and wedge resection for canine patella luxation surgery?

Answer 42

Question 43

How is a block recession done?

Answer 43

Question 44

Show some pics of tibial crest transposition?

Answer 44

Question 45

What are complications of post operation surgery?

Answer 45

* implant failure --\> re-luxation * infection * fracture / cheese-wiring of tibial tuberosity fragment

Question 46

Describe hock injuries?

Answer 46

* ligamentous injuries leading to sub – luxations / luxations (most go on to need pan-tarsal arthrodesis) * shearing injuries * osteochondrosis / OCD * fracture of tibia or tarsal bones

Question 47

Discuss greyhound fractures?

Answer 47

Acute non-weightbearing lameness of right hind Central tarsal bone --\> collapse of hock --\> fracture of 4 th tarsal, calcaneus and 5 th metatarsal bones **Treatment:** * surgical repair of fractures - refer * partial arthrodesis

Question 48

What should also be considered with hindlimb lameness?

Answer 48

**Neurological Disease :** nerve root tumour: * sciatic * lumbosacral disease **Neoplasia :** Primary: Osteosarcoma - predilection sites: distal femur, proximal tibia Fibrosarcoma, haemangiosarcoma, chondrosarcoma, synovial cell sarcoma

Question 49

Greyhounds tends to get osteosarcoma where?

Answer 49

in neck of femur

Question 50

What do cats suffer with?

Answer 50

**Hip:** cats suffer from hip dysplasia **Stifle:** cats suffer from cruciate disease and patella luxation (often associated) **Hock:** shearing injuries and luxations common Pad / Digital injuries –similar to dogs **Fractures** are common **Cat bites** are common Air gun pellet injuries are common (but often incidental findings)