Hip and Stifle Disease Flashcards
what type of disease is hip displasia?
developmental
how does hip displasia develop?
dogs are born with normal hips and laxity develops in joint capsule which allows hip to subluxate
what is the aetiology of hip displasia?
genetic (breed predisposition)
size
diet
exercise
how can diet and exercise contribute to hip displasia?
excessive / fast growth or exercise
makes presentation of hip dysplasia more likely
what species does hip dysplasia mainly affect?
mainly large and giant dog breeds
can affect small breeds and cats though
when may hip dysplasia signs present?
biphasic - present at 2 different stages of life
what are the biphasic clinical signs of hip dysplasia?
6-7 months present with laxity
adult dogs present with osteoarthritis
what are the clinical signs of hip dysplasia on gait analysis?
short stride lameness stiffness clunking of hips lateral sway of spine bunny hopping of both back legs adducted hindlimbs at walking and standing
what are the clinical signs of hip dysplasia on orthopedic examination?
pain on hip extension
clunking of hip
hindlimb muscle atrophy
crepitus on manupulation
what muscle in the hindlimbs atrophies most with hip dysplasia?
gluteals
what is used to confirm the diagnosis of hip dysplasia following suspicion from exam?
imaging
what is the common x-ray view for diagnosis of hip dysplasia?
ventrodorsal extended x-rays
what are you looking for on hip x-rays when diagnosing hip dysplasia?
hip subluxation
acetabular remodelling
osteophytes
when looking at hip dysplasia x rays what are you looking for to show some subluxation?
acetabulum should sit half way within the dorsal acetabular rim - if it is less than this there is laxity
what views should be taken to confirm hip dysplasia?
orthogonal
what is the Ortolani test used for?
testing hip laxity
how is the dog positioned for the ortolani test?
dorsal or lateral recumbacy
when will you get a negative result on the Ortolani test?
if hip is normal or dislocated
how is the ortolani test performed?
pressure applied to knee
hip is subluxated then abducted until reduced to give the angle of subluxation
what are the main treatment options for hip dysplasia?
non-surgical
surgical
what are the non-surgical management methods of hip dysplasia?
management as for OA
when will non-surgical hip dysplasia management be used?
milder cases
financial issues
what are the surgical methods of hip dysplasia management?
growth plate function
osteotomies
total hip replacement
femoral neck and head excision
what is a growth plate fusion also known as?
juvenile pubic symphysiodesis
on what dogs can growth plate fusion be performed to treat hip dysplasia?
young dog 4-5 months
what are the osteotomies performed to treat hip dysplasia?
triple / double pelvic osteotomy
what age of dog can a triple/pelvic osteotomy be performed?
less than 6-7 months
what is the role of growth plate fusion or osteotomy surgeries to treat hip dysplasia?
improves dorsal cover of the femoral head
what is avascular necrosis of the femoral head also known as?
ischaemic necrosis
Legg Calve Perthes
what is the cause of avascular necrosis of the femoral head?
trauma
ischemia to femoral head
what breeds are predisposed to avascular necrosis of the femoral head?
small breeds
why should avascular necrosis of the femoral head affected animals not be bred from?
the disease has an inherited basis consistent with an autosomal recessive gene
in what animals is avascular necrosis of the femoral head seen?
small breeds form 5 months
what are the signs of avascular necrosis of the femoral head?
unilateral hindlimb lameness
pain on hip extension and flexion
marked muscle wastage
how is avascular necrosis of the femoral head diagnosed?
imaging
what will be seen on radiographs of a patient with avascular necrosis of the femoral head?
lucent areas initially
collapse of femoral head and mushrooming when advanced
how is avascular necrosis of the femoral head treated surgically?
femoral head and neck excision
total hip replacement
how is avascular necrosis of the femoral head treated conservatively?
cage rest
when will conservative treatment of avascular necrosis of the femoral head only be used?
is mild case or an incidental finding
what is the prognosis of avascular necrosis of the femoral head?
guarded
most require salvage surgery
what is slipped capital femoral epiphysis (SFCE) also known as?
femoral neck metaphyseal osteopathy
physeal dysplasia
what are the clinical signs of slipped capital femoral epiphysis?
lameness
hip pain
what are the animals who are mainly affected by slipped capital femoral epiphysis?
young cats
male
castrated
overweight or large breed
why does castration influence slipped capital femoral epiphysis?
stops or delays the fusion of the growth plate
what radiographic view is prefurrable when diagnosing slipped capital femoral epiphysis?
frog legs so femoral head can be seen
is slipped capital femoral epiphysis traumatic?
no - atraumtic
what radiographic changes are seen in patients with slipped capital femoral epiphysis?
radiolucent line at capital physis
separation / movement between femoral head and femoral neck
resorption of femoral neck
what is the treatment for slipped capital femoral epiphysis?
femoral head and neck excision
total hip replacement
parallel pin
may spontaneously heal
why is a parallel pin no so effective at treating slipped capital femoral epiphysis?
bone resorption leaves little to pin
what is the prognosis of slipped capital femoral epiphysis?
guarded for healing - many will not heal
what is the mechanism of the cause (pathogenesis) of hip luxation?
traumatic
what is another cause of hip luxation?
spontaneously in dogs with hip dysplasia
what are the clinical signs of hip luxation?
sudden onset lameness pot trauma
altered gait
luxated leg often shorter
what direction does the hip luxation usually take?
craniodorsal
what is the gait of an animal with hip luxation?
stifle out, hock in and leg adducted
what radiographs can be used to diagnose hip luxation?
2 orthogonal radiographs (VD and Lat)
check for concurrent fractures or hip dysplasia
why should you check for concurrent fractures or hip dysplasia on orthogonal radiographs of a patient with luxation?
may alter prognosis
how may hip luxation be diagnosed on exam?
assessment of lameness assessment of pain and crepitus palpation of bilateral landmarks to feel for normal and abnormal) limb length thumb displacement test
what is the thumb displacement test for hip luxation?
manipulate hip with thumb between tuber ischii and greater trochanter
if dislocated with thumb will remain in the notch while hip is manipulated
how will landmarks often line up in a hip luxation?
tuber ischii, crest of ileum and greater trochanter will line up rather than forming a triangle
what is essential for diagnosing hip luxation?
radiographs and CT
what can the physical exam and clinical signs of hip luxation be complicated by?
presence of fractures of the pelvis and proximal femur
what must be provided to hip luxation as soon as possible?
analgesia - opioid (full alpha agonist) and/or NSAID
what should patients with hip luxation be checked for?
concurrent injuries (e.g. RTA)
what does treatment of hip luxation depend on?
presence of pre-exisiting disease (e.g. hip dysplasia)
duration of luxation
concomitant orthopedic injuries
what are the management options for hip luxation?
closed reduction +/- sling
open reduction
salvage optons - FHNE or THR
what is the aim of a salvage surgery?
maintain normal function but not anatomy
when should closed reduction be attempted?
early