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
why should closed reduction be attempted early?
the longer the luxation has been present the more difficult to reduce it is
there will also be more cartilage damage
when should a closed reduction never be attempted?
acetabular or femoral head fractures chronic luxations other injuries such as pelvic fractures that prevent reduction if cartilage evaluation is needed if hip dysplasia
how is closed reduction performed?
- Animal anaesthetised
– Assistant needed to hold on to dog or may be 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 the acetabulum
– Confirm reduction with two orthogonal xrays
– Ehmer sling or cage rest post reduction
what is needed post closed hip luxation reduction?
Ehmer sling or cage rest
what are the options for open (surgical) reduction of hip luxation?
toggle - replaces round ligament transarticular pin prosthetic capsular repair iliofemoral suture priamry capsular repair
how long does surgical repair of hip luxation by transarticular pin and
iliofemoral suture last?
temporary until joint capsule and ligament of the femoral head heal
what is the prognosis with treatment of hip luxation?
good in 75% of cases
what are the complications associated with hip luxation?
OA will form
recurrent dislocation is possible
what is patella luxation?
displacement of the patella from the groove in distal femur
what direction can the patella luxate?
medial or lateral
what direction does patella luxation occur mostly?
medial
in how many limbs does patella luxation often occur?
often bilateral
in what breeds is patella luxation common?
small breed
what is medial patella luxation common in?
large and small dogs
cats
what animals is lateral patella luxation common in?
large breed dogs
what direction does patella luxation occur in, in cats?
medially most commonly
what age are most patella luxation patients?
young as usually developmental and may be heraditory
what is traumatic patella luxation more common in?
cats
what are the predisposing developmental abnormalities to patella luxation?
femoral torsion
lateral bowing of distal femur
medially positioned tibial tuberosity
hypoplasia of medial femoral condyle
what is characteristic of patella luxation?
giat
what will animals with patella luxation avoid doing?
flexing or extending the stifle as quads don’t function
how do animals walk with bilateral medial patella luxation?
cowboy stance
stifles flexed
wide based stance
what is found on clinical exam of a patient with patella luxation?
stifle discomfort
patella clicks on the manipulation of the stifle
laxity of patella on stifle extension
what is the gait like of an animal with bilateral lateral patella luxation?
knock knees
how is patella luxation graded?
I - IV
describe grade I patella luxation
patella normally within groove
returns spontaneously when luxated manually
describe grade II patella luxation
patella normally within groove
can be luxated and will remain so when released
describe grade III patella luxation
patella normally outside groove
can be manipulated back into groove
describe grade IV patella luxation
patella normally outside groove
cannot be reduced by manipulation
what does the prognosis of patella luxation depenf on?
severity
what is the grade of most patella luxation cases?
II
is imaing usually necessary for patella luxation?
no - may well be normal unless patella actually luxated
what can imaging of patella luxation be used for?
checking for concurrent disease
how can patella luxation be treated?
tibial tuberosity transposition
deepening of trochlear groove
soft tissue repairs
what is the aim of tibial tuberosity transposition surgery?
realigns tibial tuberosity and pull of the quadriceps with teh groove
how can the trochlear groove be deepened?
wedge or block
how is deepening of the trochlear groove performed?
block or wedge is removed from femur at the trochlear groove
this is removed and bone from beneath is cut away
the block or wedge is then replaced to maintain the articular cartilage
what are the 2 soft tissue patella luxation surgeries?
release - side of normal luxation has tissues cut to reduce pull
imbrication
what is the post op care for a patient who has had patella luxation repair?
consider a support dressing if severe
multimodal analgesia
gradual increase in exercise after 3-6 weeks strict rest
how much strict rest is needed following patella luxation surgery?
3-6 weeks
what is the prognosis of patella luxation repair?
deteriorates with increasing grade of luxation
what is the prognosis of patella luxation for small dogs?
90-95%
what is the prognosis for dogs over 20kg with patella luxation?
significantly higher risk of complications or repair failure
what is the most common cause of hindlimb lameness in dogs?
cranial cruciate ligament disease
what is the disease process of cranial cruciate ligament disease?
poorly understood
what are the functions of the cranial cruciate ligament?
limit cranial drawer
limit hyperextension of stifle
limit internal rotation of stifle
what is cranial drawer?
movement of tibia tibia in relation to femur
what are the causes of cranial cruciate ligament disease?
major trauma
degeneration
inflammatory arthropathy
tibial plateau angled by growth abnormality
is cranial cruciate ligament disease often caused by major trauma?
no
what trauma can case cranial cruciate ligament disease?
hyperextension
what dogs is degenerative cranial cruciate ligament disease most common?
middle aged
female
what is the most common cause of cranial cruciate ligament disease?
degeneration
what is acute presentation of cranial cruciate ligament disease due to?
ligament rupture
what is the most common presentation of degenerative cranial cruciate ligament disease?
low grade lameness
what breeds are predisposed to cranial cruciate ligament disease?
retriever
lab
westie
why may some breeds be predisposed to cranial cruciate ligament disease?
proteolytic changes weaken ligament
what condition is already present in degenerative cranial cruciate ligament disease cases?
degenerative joint disease
what percentage of degenerative cranial cruciate ligament disease occurs bilaterally?
30-50%
what conditions in young, large breed dogs often lead to cranial cruciate ligament disease?
inflammatory arthropathy
tibial plateau angled by growth abnormaility
at what age will dogs with inflammatory arthropathy and tibial plateau angled by growth abnormality present with cranial cruciate ligament disease?
6m - 6 years
why may patients with cranial cruciate ligament disease not always have a positive cranial drawer?
there are 2 bands to the ligament and only one may have ruptured
what are the 2 bands of the cranial cruciate ligament?
caudolateral
craniomedial
when are the caudolateral bands of the cranial cruciate ligament tight?
only in extension
when are the craniomedial bands of the cranial cruciate ligament tight
always
what band of the cranial cruciate ligament is usually affect by partial tears?
craniomedial band
why must the cranial drawer jest be performed in extension and flexion?
partial tears or different band rupture
how is cranial cruciate ligament disease diagnosed?
gait analysis
physical exam
what is found in the physical exam that suggests cranial cruciate ligament disease?
stifle pain especially on extension effusion crepitus media buttress instability on cranial drawer and tibial thrust tests
what is assessed on the cranial drawer test?
abnormal movement between the femur and tibia
how should the cranial drawer test performed?
grip femur and tibia
move tibia cranially
should be resistance / no movement
under what conditions should the cranial drawer be tested?
flexion and extension
what are the issues are the cranial drawer test?
can be painful
can be resisted in the conscious animal
how should the tibial thrust test be performed?
hand over stifle with finger on tibia
mimic weightbearing on hock with other hand (flex and extend foot)
finger on tibia will move forward if more mobile (should not be)
what are the advantages of the tibial thrust test?
easier in conscious animals and those standing
harder to resist
more comfortable
what is the disadvantage of the tibial thrust test?
more difficult
what is seen in the joint with cranial cruciate ligament disease?
reduced infrapatellar fat pad due to compression by synovial fluid
increased synovial fluid
new bone formation
what does new bone formation indicate?
DJD
what does new bone formation indicate?
DJD
when is diagnosis of cranial cruciate ligament disease not straightforward?
not clearly unstable
DJD on radiograph
effusion
what is usually happening with problem cranial cruciate ligament disease cases where they do not heave clearly unstable joints but there is DJD and effusion?
usually cruciate disease with partial rupture
other arthropathies possible
consider arthrocentesis
when is conservative treatment of cranial cruciate ligament disease used?
if unsure of rupture
what are the 2 types of surgery to correct cranial cruciate ligament disease?
intra or extra articular replacements
corrective ostotomy
what is the intracapsular surgical treatment for cranial cruciate ligament disease?
over the top
what is the extracapsular surgical treatment for cranial cruciate ligament disease?
fabello-tibial sutures
what is the purpose of extra or intracapsular surgical treatment for cranial cruciate ligament disease?
sutures used to mimic function of cranial cruciate ligament
what is the corrective osteotomy surgical treatment for cranial cruciate ligament disease?
TPLO
what happens during a TPLO?
tibial plateau angle is altered to stop tibial thrust
what is the post-op care needed for cranial cruciate ligament disease treatment?
varies with procedure
what analgesia is needed post op cranial cruciate ligament surgery?
NSAIDs for 10-14 days
opioids for 24-48 hours
what are the post op instructions and guidance for owners following cranial cruciate ligament disease repair?
surgery will not cure the dog but can slow arthritis progression
limited exercise is essential to protect repair
physio and hydro are important and will benefit recovery
the joint will never be normal again
what is the complication rate for cranial cruciate ligament disease surgeries?
10-15%
what is the success rate for cranial cruciate ligament disease surgeries?
85-90%
what procedures to repair cranial cruciate ligament disease give the best outcome?
osteotomy
what is the least effective cranial cruciate ligament repair technique?
over the top (intraartiular repalcement) - fascia pulled into joint
what does evidence suggest about weight-bearing following cranial cruciate ligament repair?
early is better with TPLO compared to Fabellotibial suture
what is the risk with TPLO surgery?
higher infection rate than F-T suture
higher severe complication rate
how long can full recovery from cranial cruciate ligament surgery take?
several months
what cannot be prevented by cranial cruciate ligament disease surgery?
DJD progression eventually
intermittent OA flare up in later life
how many patients with cranial cruciate ligament disease have meniscal tears?
50%
what must be performed on cranial cruciate ligament disease surgery to assess meniscus?
arthrotomy
what meniscus usually tears?
medial
what should be done if a meniscal tear is found on arthrotomy?
debride torn portion
leave unaffected meniscus
what are late meniscus tears?
those missed during surgery or those that happen after
how many meniscal tears are late?
up to 20% of tears