Hips and Stifles

Question 1

Describe how hip dysplasia occurs.

Answer 1

Developmental - dogs born with normal hips, laxity develops in joint capsule
Can be due to genetics / size / diet / exercise

Question 2

What is the typical signalment for hip dysplasia patients?

Answer 2

Mainly large/giant breed dogs but also small breeds/cats

Biphasic clinical signs - at 6-7 months (development of laxity) / adult (onset of osteoarthritis

Question 3

What are the gait-related clinical signs of hip dysplasia?

Answer 3

Short stride, stiffness, clunking of hips
Lateral sway
Bunny hopping
Adducted hindlimbs

Question 4

What clinical signs of hip dysplasia can we see on orthopaedic examination?

Answer 4

Pain on hip extension
Clunking
Hindlimb muscle atrophy
Crepitus

Question 5

How can we use radiography to diagnose hip dysplasia?

Answer 5

Ventrodorsal extended X-rays
Looking for hip subluxation/acetabular remodelling/osteophytes
Orthogonal views

Question 6

What other test for hip dysplasia can be done?

Answer 6

Ortolani test
Dog in dorsal/lateral recumbency
Test of hip laxity

Question 7

How can we non-surgically treat hip dysplasia?

Answer 7

Management of osteoarthritis

NSAIDs, rest, hydrotherapy, diet

Question 8

How can we surgically manage hip dysplasia?

Answer 8

Young dogs < 6 months = growth plate fusion (juvenile pubic symphysiodesis) / osteomies (triple/double pelvic osteotomy)
Total hip replacement
Femoral head and neck excision

Question 9

What are the alternative names for avascular necrosis of the femoral head?

Answer 9

Ischaemic necrosis

Legg Calve Perthes

Question 10

Why does avascular necrosis of the femoral head occur?

Answer 10

Trauma, ischaemia
Small breed disposition
Genetic basis - should not be bred from

Question 11

What are the clinical signs of avascular necrosis of the femoral head?

Answer 11

Small breeds from 5 months
Unilateral hindlimb lameness
Pain on hip extension and flexion
Muscle wastage

Question 12

How can we diagnose avascular necrosis of the femoral head?

Answer 12

Radiography

Lucent areas initially, then collapse and mushrooming

Question 13

How can we treat avascular necrosis of the femoral head?

Answer 13

Surgery - femoral head and neck excision / total hip replacement
Conservative - cage rest

Question 14

What is the prognosis for avascular necrosis of the femoral head?

Answer 14

Guarded - usually require salvage surgery

Question 15

What are the other names for slipped capital femoral epiphysis?

Answer 15

Femoral neck metaphyseal osteopathy

Physeal dysplasia

Question 16

What are the clinical signs/signalment for slipped capital femoral epiphysis?

Answer 16

Lameness and hip pain

Young, male, castrated

Question 17

How can we diagnose slipped capital femoral epiphysis?

Answer 17

Radiography
Radiolucent line at capital physis
Separation/movement between femoral head and femoral neck
Resorption of femoral neck

Question 18

How can we treat slipped capital femoral epiphysis?

Answer 18

Salvage surgery - femoral head and neck excision / total hip replacement / parallel pin

Question 19

What is the prognosis for slipped capital femoral epiphysis?

Answer 19

Guarded for healing - usually do not heal

Question 20

Why can hip luxation occur?

Answer 20

Usually traumatic e.g. RTA, fall

Can be seen spontaneously in dogs with hip dysplasia

Question 21

What are the clinical signs of hip luxation?

Answer 21

Sudden onset lame post-trauma
Gait - stifle out, hock in and leg adducted
Luxation usually in craniodorsal direction
Variable lameness (moderate to non-weightbearing)
Variable pain and crepitus

Question 22

How can we diagnose hip luxation?

Answer 22

Leg length comparison
Thumb displacement test
Palpation of landmarks
Radiography - two orthogonal views, check carefully for concurrent fractures/hip dysplasia that may alter prognosis

Question 23

What does treatment for hip luxation depend on?

Answer 23

Presence of pre-existing disease e.g. hip dysplasia
Duration of luxation
Concomitant orthopaedic injuries

Question 24

How can we treat hip luxation?

Answer 24

Analgesia (opioid +/- NSAID)
Closed reduction +/- stabilisation (Ehmer sling/ESF)
Open reduction
Salvage options - femoral head and neck excision / total hip replacement

Question 25

When would we never attempt closed reduction of a hip luxation?

Answer 25

``` Acetabular or femoral head fractures Chronic luxations Other injuries e.g. pelvic fractures preventing reduction Evaluation of cartilage needed Hip dysplasia ```

Question 26

How do we carry out a closed reduction on a hip luxation?

Answer 26

Animal anaesthetised Assistant needed to hold on to dog to ensure is not pulled off table Extend, adduct and externally rotate limb to lift femoral head over dorsal acetabular rim Then abduct and internally rotate to sit femoral head into acetabulum Confirm reduction with two orthogonal X-rays Ehmer sling/cage rest post-reduction

Question 27

What options do we have for open reduction of hip luxation?

Answer 27

``` Toggle Transarticular pin Prosthetic capsular repair Iliofemoral suture Primary capsular repair ```

Question 28

What is the prognosis for hip luxation patients?

Answer 28

Good in 75% of cases Osteoarthritis will form Recurrent dislocation possible

Question 29

How does patella luxation occur?

Answer 29

Displacement of patella from groove Medial or lateral, often bilateral Common in small breeds - usually medial luxation Lateral luxation more common in large breeds Can occur in cats Most cases are developmental, possible hereditary Occasionally traumatic

Question 30

How can we diagnose patella luxation?

Answer 30

Characteristic gait - nay avoid flexing/extending stifle Clinical exam - stifle discomfort, patella clicks on manipulation of stifle, look for patella laxity with stifle in extension Imaging - not usually necessary for diagnosis

Question 31

How is patella luxation graded?

Answer 31

I = least serious, IV = most serious

Question 32

How can we surgically treat patella luxation?

Answer 32

Tibial tuberosity transposition Deepen trochlear groove - wedge / block Soft tissue - release / imbrication

Question 33

How do we care for patella luxation patients post-op?

Answer 33

Consider support dressing Analgesia - multimodal Gradual increase in exercise after 6 weeks' strict rest

Question 34

What is the prognosis for patella luxation patients?

Answer 34

Deteriorates with increasing grade of luxation 90-95% success rate in small dogs > 20kgs significantly higher risk of complications/failure

Question 35

What is the function of the cranial cruciate ligament?

Answer 35

Limit cranial draw Limit hyperextension Limit internal rotation

Question 36

What are the causes of cranial cruciate ligament disease?

Answer 36

Major trauma - uncommon, usually hyperextension Degeneration - common, can present acutely, certain breeds predisposed, degenerative joint disease already present, can occur bilaterally Young large breed dogs - 6mth-3yrs, partial tearing, degenerative joint disease Inflammatory arthropathy Tibial plateau angled by growth abnormality

Question 37

How can we diagnose cranial cruciate ligament disease?

Answer 37

Gait analysis Physical exam - stifle pain, effusion, crepitus, medial buttress Instability tests - cranial draw / tibial thrust Imaging - increased joint fluid, new bone formation

Question 38

How can we treat cranial cruciate ligament disease?

Answer 38

Conservative Intra-/extra-articular replacements - intracapsular = over the top, extracapsular = fabello-tibial sutures Corrective osteotomy

Question 39

How do we care for cranial cruciate ligament disease patients post-op?

Answer 39

Varies with procedure NSAIDs for 10-14 days, opioids for 24-48rs Surgery does not 'cure' dog, only slows progression of arthritis Physiotherapy important

Question 40

What is the prognosis for cranial cruciate ligament disease?

Answer 40

Complication and success rates similar between techniques Degenerative joint disease inevitably progresses in any dog Full recovery can take several months Likely to intermittent flare-ups of osteoarthritis in later life

Question 41

What injury can we often see alongside cranial cruciate ligament disease?

Answer 41

Meniscal tears - approx. 50% incidence in dogs with CCLD Must perform arthrotomy at surgery to check for this Usually medial meniscus that tears Debride torn portion, leave unaffected meniscus