Hip Dysplasia Flashcards
Define hip dysplasia
Complex disease which has been defined as a varying degree of hip laxity, permitting subluxation during early life.
What does hip dysplasia give rise to, which inevitably leads to OA?
Remodeling of acetabulum and femoral head.
There is a direction correlation between what and the development of OA ?
Hip laxity
Which breed type has a low incidence of hip dysplasia?
Sight hounds
Dog Breeds most commonly affected by hip dysplasia? (5)
GSD
Rottweiler
Golden retriever
Labrador
Saint bernard
(Mostly larger breeds)
Cat breeds pre disposed to HD? (3)
Persian
Devon rex
Maine Coon
What is the sex pre disposition to HD?
There isnt one
What genetic trait is HD?
Polygenic
What environment factors influence HD? (5)
Weight
Growth rate
Nutrition
Muscle mass
hormones
What is the heritability range of HD?
0.2-0.6
True or false
At birth all canine hip joints are normal?
True: but they develop abnormally based on the genetics of the dog and environmental influences.
What happens within the hip joint anatomically to create the abnormal HD? (4)
- Loss of joint congruency
- Stretch of ligament of head of femur
- Loss of dorsal acetabular rim
- Subluxation of femoral head
Following the stretch of the joint capsule; what des this lead to? (4)
- Further subluxation and therefore additional remodelling of dorsal acetabular rim + femoral head + articular cartilage degeneration
How does the femoral head become mis shapen with HD?
Acetabulum infills with bone
Femoral neck thickens
Acetabulum = shallower
Femoral head becomes mis shapen
What happens at skeletal maturity which makes the hip joint more stable? (2)
Joint capsule thicken
Improved muscle mass
What causes pain with HD in younger dogs? (5)
Joint laxity
Stretching or tearing of joint capsule
Stretch or tear of ligaments
Stretch or tear of muscle
Microfracture of dorsal acetabular rim
What causes pain with HD in older dogs?
OA
Is HD mono or biphasic?
Monophasic - progresses throughout life
Is bunny hopping seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Immature
Are behaviour changes seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Mature
Is rarely acute lameness Is bunny hopping seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Mature
Is Pelvic swaying when walking seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Immature
Is inactivity stiffness seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Mature
Is apparent weakness of pelvic limbs seen with HD in immature dogs (4-12mo) or mature dogs (>12mo)?
Immature
List clinical signs of HD in immature dogs (4-12mo) (8)
Variable lameness
Apparent weakness of pelvic limbs
Pelvic swaying when walking
Bunny hopping
Difficulty rising
Reluctance to exercise
Difficulty jumping
Difficulty with stairs
List clinical signs of HD in mature dogs (>12mo) (6)
Behaviour change
Difficulty rising
Exercise intolerance
Difficulty jumping
Rare to see acute lame
Inactivity stiff
Why may the greater trochanter be prominent in young dogs?
Poorly developed gluteal m.
With HD when is pain often seen with manipulation?
Extension
When might you be able to feel hip instability?
When hip joints are palpated while the dog is walking
What 3 tests can be performed under GA for HD?
Ortolani
Barlow
Barden
Define ortolani test
In lateral recumbency one hand is placed on the dorsal aspect of the pelvis whilst the other hand holds the stifle. Firm pressure is applied from the stifle in a dorsal direction. At this point, subluxation of the hip may be appreciated. Whilst this pressure is maintained the limb is gently abducted until a clunk is detected (positive Ortolani sign) which is the reduction of the femoral head into the acetabulum. As the limb is adducted with dorsal pressure maintained subluxation of the hip will occur.
With the ortolani test - what is the reduction angle?
The angle between the limb and the table at the time of reduction
With the ortolani test - what is the subluxation angle?
The angle between the table and limb when this occurs
What clinical signs of HD are seen with cats? (3)
less active,
reluctant or hesitant to jump
exhibit behavioural changes.
Define a positive barden test
If the greater trochanter displaces >0.5 cm laterally then the test is considered positive.
What is the Barlow test?
This is the detection of femoral head subluxation and is essentially forms the first part of the Ortolani test.
What is the barden test?
This is known as the hip lift test and is again performed with the animal in lateral recumbency. The femur is grasped and the limb is lifted laterally whilst feeling the greater trochanter with the other hand.
HD differentials, is this for skeletally immature or skeletally mature animals?
Myaesthenia gravis
Immature
HD differentials, is this for skeletally immature or skeletally mature animals?
Avascular necrosis of femoral head
Immature
HD differentials, is this for skeletally immature or skeletally mature animals?
Slipped capital femoral epiphysis
Immature
HD differentials, is this for skeletally immature or skeletally mature animals?
Common calcanean tendinopathy
Mature
HD differentials, is this for skeletally immature or skeletally mature animals?
Stifle OCD
Immature
HD differentials, is this for skeletally immature or skeletally mature animals?
Lumbosacral Dx
Mature
List HD differentials in skeletally immature animals (12)
Avascular necrosis of the femoral head
Slipped capital femoral epiphysis
Panosteitis
Lumbosacral disease
Patellar luxation
Cranial cruciate ligament avulsion
Cranial cruciate ligament disease
Stifle osteochondrosis
Septic arthritis
Spinal disorders
Myopathies
Myasthenia gravis
List HD differentials in skeletally mature animals (7)
Cr Crcuiate ligament dx
Patella luxation
Lumbosacral dx
Other spinal dx
Common calcanean tendinopathy
Septic arthritis
Myotpathy
What views of xrays to diagnose HD?
The hip extended view is the standard projection taken As always, orthogonal views should be obtained to include a lateral projection of the pelvis.
True or false
Recently the hip-extended view has been reported to have poor precision and predictive accuracy for the diagnosis of canine hip dysplasia.
True
What is the frogleg pelvic xray good for with HD?
assess acetabular infilling
A ventrodorsal extended projection of the hips can give the appearance of ? of the femoral head even when significant hip laxity is present.
minimal subluxation
What may better assess joint laxity in the young patient and has good correlation between the distraction index calculated and the susceptibility to osteoarthritis?
The “Penn Hip” programme with ventrodorsal extended, compression and distraction views
Manual restraint required - cannot perform in UK, however modifications for use with aids.
What should radiographs be asses for with HD? (5)
Femoral head subluxation
Medial joint space widening
Dorsal acetabular rim remodelling
Remodelling of femoral head and neck
Osteophytes / enthesiophytes:
Where may osteophytes or enthesiophytes form with HD? (3)
Acetabular fossa
Cranial and caudal acetabular edges
Femoral head and neck
What are the aims of HD treatment? (3)
Alleviate pain
Improve function
Reduce OA progression
What are non surgical options for HD? (6)
Weight control
Exercise management
Therapeutic agents
Regenerative medicine
Nutrition management
Complement therapy
How long shoulds NSAIDS be given with HD to fully assess response?
2 weeks
What is the NSAID - NSAID washout period
5 days
What is the monoclonal antibody that can be used for HD?
Bedinvetmab
What surgical approaches have been described to improve the congruence by ventroversion of the acetabulum? (3)
Juvenile pubic symphysiodesis (JPS) and double or triple pelvic osteotomy (DPO or TPO)
Define JPS
Juvenile pubic symphysiodesis
What is involved with JPS (Juvenile pubic symphysiodesis?
insulting the pubic symphysis e.g. with electrosurgery so that it stops being involved in endochondral ossification.
Which patients do JPS benefit the most?
<16 weeks
Mild - moderate hip laxity
What % of patients can be managed non surgically
76%
What are the complications of JPS? (3)
Loss of pelvic canal diameter
Thermal damage
Incisional oedema
When is a TPO best performed?
Under 10 months
Where has TPO been shown to be efficacious?
Skeletally immature
Complications of DPO/TPO? (4)
Screws loosen
Failure
Pelvic canal narrow –> dysuria/constipation
Pelvic canal narrow –> Sciatic/obturator n damage
Where is the osteotomy with DPO?
Ileum and pubis
Where is osteotomy with TPO?
ilium, pubis and ischium are carried out in allowing rotation of the acetabulum to allow greater coverage of the femoral head.
Salvage procedure for HD?
FHNE
What is a reconstructive surgery for HD?
THR - total hip replacement
When is THR indicated?
Persistent pain/lane where non surgical has failed.
What is the difference between cement and cementless THR?
Not evaluated/define
What ae can a THR be performed?
THR can be performed in both skeletally immature and mature animals and indeed there are a subset of young dogs with extreme hip dysplasia that can benefit from early total hip replacement.
Complications of THR? (6)
Fractures (femoral + pelvic)
Luxation
Aseptic loosening
Implant infection
Osteomyelitis
Sciatic neuropraxia
Implant failure
How long should exercise be significantly restricted for post THR?
first month
Following the initial significant rest - what exercise regime should follow with THR?
Gradual return over following 8-12 weeks
Major reasons not to perform THR? (2)
High finance
Poor availability
How to control hip dysplasia
Breeding schemes
What is Legg -Calve-Perthes dx?
Avascular necrosis of the femoral head also known as Legg-Calve-Perthes disease is characterised as a non-inflammatory local ischaemia, which leads to necrosis of the trabecular bone and collapse of epiphysis
How does Legg-Calves-Perthes lead to pain/dysfunction?
This heals with new bone but the femoral head and neck are malformed to a greater or lesser extent, depending on the severity of the ischaemia,
What genetic trait has been shown to be a factor causing Legg Calve Perthes
Autosomal recessvie
Which breeds are pre disposed to Legg Calve Perthes? (2)
miniature poodle
WHWT
(small breed most common)
What age dogs are affected by Legg Calve Perthes?
Sex?
4-11mo
No sex effect
How many cases of Legg Calve Perthes are bilateral?
12-16.5%
How to diagnose Legg Calve Perthes?
Xrays
CT more sensitive in early stages
Clinical signs of Legg Calve Perthes?
Mild cases can be sub-clinical but more severe cases can result in a range of lameness from mild and intermittent to acute non-weight bearing.
Physical exam findings for Legg Calve Perthes? (3)
Pain
Crepitus
Muscle atrophy
What x ray views should be taken for Legg Calve Perthes?
Frogleg (flexed) VD
Extended VD
Lateral
What do xrays reveal with Legg Calve Perthes? (3)
Radiographs reveal focal bony lysis of the femoral head (‘moth eaten’ or ‘apple coring’)
Flattening and mottling of the femoral head
Collapse and thickening of the femoral neck later in the disease process.
What treatment for Legg Calve Perthes is successful in 84-100%?
FHNE
When is conservative management an option with Legg Calve Perthes?
Mild affected and minimal progression
