Common causes of hindlimb lameness: hip and hock

Question 1

Which animals most often get hip dysplasia?

Answer 1

dogs very common: large breeds
rare in cats

strong genetic component, heritability
some environmental influence
polygenetic

Question 2

How do animals develop hip dysplasia?

Answer 2

born with normal hips
1-2mo: laxity develops in joint
hip subluxation (acetabular rim microfracture, cartilage erosion, inflammation and pain)
increased joint fluid, capsule thickening
bone remodeling
OA

Question 3

How can diet influence hip OA?

Answer 3

ad lib fed dogs had an earlier onset (6 vs 12 yo) and increased severity

Question 4

What is the signalment for hip dysplasia?

Answer 4

large breeds most commonly: labs, GSD, goldens
initially present 6-7mo
+/- mature with lameness due to OA

bunny hopping, lameness, click/clunk noise, lateral pelvic swaying, muscle atrophy
older dogs: slowing, won’t jump, difficulty rising

Question 5

What are the key findings in an ortho exam indicating hip dysplasia?

Answer 5

PAIN on hip extension
+/- abduction
+/- clunking, muscle atrophy

**make sure its not a cruciate rupture in adult middle-aged-older!

Question 6

What do we look for in radiographs of young animals vs hip dysplasia?

Answer 6

acetabular coverage femoral head: should be over 50%

early secondary chnages

luxoid hips

Question 7

What do we look for in radiographs of old animals vs hip dysplasia?

Answer 7

thickening +/- capsule mineralisation
osteophytes/new bone formation
flattening femoral head “ mushroom”
flattening acetabulum “dishing”
subluxation to completely luxoid

Question 8

What are the palpation tests we can do on young dogs vs hip dysplasia?

Answer 8

testing of hip laxity

bardens test
ortolani test

Question 9

What is the prognosis of animals with hip dysplasia with non-surgical management?

Answer 9

70% functionally doing well by 12-15mo
joints stabilise by fibrosis

this should always be first line in young and old

Question 10

What is the conservative management of hip dysplasia?

Answer 10

need to do fully and for over 3 months

1. exercise adjustment: consistent regular short exercise with small increases every 2 weeks
2. Physical therapies: physio and hydro (non-loaded)
3. diet: keep lean or lose weight, omega3 fatty acid supplementation
4. Anti-infl. pain killers: nsaids

Question 11

What are prophylactic surgical treatments of hip dysplasia?

Answer 11

surgery to improve the fit of the hip joint, needs to be done early with conservative management

pelvic osteotomy
juvenile pubic symphysodesis

Question 12

What are definitive surgical treatments for hip dysplasia?

Answer 12

arthroplasty

femoral head and neck excision FHNE/ostectomy
total hip replacement

Question 13

What is the common hx and signalment for legg calve perthes/avascular necrosis?

Answer 13

progressive hind limb lame
subclinical to severe non-weight bearing lame
small terriers, yorkies, chichis, schnauzers, poodles
4mo

pain hip extension and abduction, muscle atrophy

Question 14

How does legg calve perthes/avascular necrosis develop?

Answer 14

ischaemia of femoral head
necrosis of head trabeculae
collapse of epiphysis during walking (fragmentation phase)
secondary thickening
re-vascularisation and new bone formation with malformation of femoral head (re-ossification phase)
severe OA

Question 15

What does legg calve perthes/avascular necrosis look like on xrays?

Answer 15

early: moth eaten/apple core
later: flattening/mottling

Question 16

What is the treatment for legg calve perthes/avascular necrosis?

Answer 16

conservative is ineffective
femoral head and neck excision
THR

send for histology +/- culture

Question 17

What should we do when suspecting hip luxations?

Answer 17

usually significant trauma
concurrent injuries
major body system assessment
thoracic radiographs when stable +/- lower urinary tract work up

Question 18

What is the treatment for hip luxations?

Answer 18

closed reduction as soon as stable for GA
always try IF no bony damage on radiographs

surgery when multiple inuries, concurrent fractures hip, failure closed reduction

Question 19

What are the common causes for lameness in the tarsus?

Answer 19

osteochondritis dissecans OCD

degeneration: achilles degeneration/rupture and plantar ligament collapse

trauma: fractures/luxations/soft-tissue damage/ligament rupture

Question 20

What is OCD in the tarsus?

Answer 20

not common, developmental disease, failure of endochondral ossification

cartilage/larger osteochondral flap: often medial ridge
osteoarthritis tarsocural joint/instability

5mo-1y, older with OA

Question 21

What is the history and ortho exam results in an animal with tarsus OCD?

Answer 21

hindlimb lame
upright hocks

tarsal effusion or thickening
+/- reduced flexion, crepitus, pain
pain on flexion and extension/decreased ROM

Question 22

What is the treatment for tarsal OCD?

Answer 22

mild clinical signs = conservative
significant clinical signs = surgical (arthrotomy/arthroscopic removal of fragment or pantarsal athrodesis)

early surgery better results but study showed surgical treatment resulted in a worse outcome

Question 23

What are the common problems of the achilles tendon?

Answer 23

traumatic rupture/transection

degenerative failure (middle ages large breed): swelling/thickening, flat footed

Question 24

What happens in achilles degeneration?

Answer 24

3 parts: gastroc, combined (G-ST-BF), SDF
dropped hock of variable severity
claw foot

Question 25

What is the treatment for achilles degeneration?

Answer 25

immobilize
resect and reconnect
prosthetic augmentation
pantarsal arthrodesis
direct repair (traumatic)

Question 26

What is plantar collapse?

Answer 26

ligament degeneration and collapse
middle aged dogs
progressive lameness

increased movement at intertarsal joints

Question 27

What is the treatment for plantar collapse?

Answer 27

arthrodesis