Hip dysplasia Flashcards
Laxity vs dysplasia
Hip dysplasia is a hereditary condition
- Puppies are born with normal hips, they then develop abnormally leading to hip dysplasia
Many dogs will have laxity early in life, but this does not predict dysplastic changes later
Risks for hip dysplasia
Diet - weight essentially (overweight will put more load on the joints)
Exercise - exercising young puppies excessively will cause them to have all sorts of joint issues
Common breeds that develop hip dysplasia
labradors, GSDs, Rotties, Goldens and (increasingly) cross breeds
At what age do signs of hip dysplasia start to show?
Typically 6-7mo but may be older
Clinical signs of hip dysplasia
difficulty rising,
abnormal gait,
bunny hopping,
pelvic limb lameness,
clicking/clunking of the hips,
May be sensitive around back end on palpation
Possible causes of pelvic limb lameness
Hip dysplasia
Cranial cruciate ligament disease
Patellar luxation
Neurological disease
- IVD disease
- lumbosacral disease
- degenerative myelopathy
Signs of hip dysplasia on orthopaedic exam
Asymmetric muscle mass, esp. quads and gluteals
Sensitivity over hind quarters
Pain on hip extension, abduction
Reduced range of motion, crepitus (DJD)
Can’t really detect effusion in the hip
Asymmetric pad wear
Typical gait observations for hip dysplasia
Will typically hop up steps, moving both hind limbs together to reduce pain
Shortened, slower stride on affected limb
Lateral sway
Bunny hopping when bilateral
Often (60%) bilaterally affected, may well be asymmetric
Differential diagnoses for hip dysplasia
Avascular necrosis of the femoral head (younger, small breed dog)
Fracture (pelvis, proximal femur) (traumatic history)
Luxation (traumatic history)
Psoas injury (soft tissue injury - psoas muscle inserts on greater trochanter) (difficult to distinguish)
Sciatic pathology
Neoplasia (bone or joint)
Sepsis
Ortolani test
Dog in dorsal recumbency
Dorsal pressure on the stifle
Abduct to detect reduction
Adduct to detect subluxation
When they have hip dysplasia when you press down it will sub-lux and then clunk into place when abducted
Barden hip lift
Dog in lateral recumbency
Proximal femur is palpated
Apply dorsal lift to femur
Then reduce with thumb
Palpable movement indicates laxity
Questionable value
Radiographic evaluation of hip dysplasia
General screening x-rays (2 view)
BVA-kennel club or OFA scoring films
Assessment of anatomy and presence/absence of secondary changes
May be supplemented by measures of hip laxity
○ PennHip
○ Controversial in UK due to need for manual restraint
○ requires hip extension so if dog is painful you won’t get good hip x-rays
○ good for looking at femoral neck anatomy
Hip subluxation on x-ray
Dorsal acetabular cover
Norberg angle
Distraction index: a measure of passive joint laxity
Norberg angle
ideally angle is >105 degrees
Distraction index
a measure of passive joint laxity
DI < 0.3 - good prognosis
DI > 0.7 - poor prognosis
Goals of therapy for hip dysplasia
Manage pain
Improve range of motion
Improve limb function
Improve muscle mass and strength
Improve activity level
Improve quality of life
Conservative treatment options for hip dysplasia
Rest
Diet management
Exercise restriction after rest
Small walks a few times a day rather than one long walk
Rehab
Physiotherapy including hydrotherapy
Medical management
Medical management for hip dysplasia
NSAIDs
□ Aspirin
□ Carprofen
□ Robenacoxib
□ Meloxicam
Nutraceuticals
Chondroprotectants - much better early on in the disease process (DMOADs)
□ Hyaluronic acid, PSGAG
Analgesics
□ Paracetamol
□ Tramadol
□ Gabapentin
Surgical management of hip dysplasia
Pain reduction
Mechanical realignment
Excision arthroplasty
Joint replacement
Pectineal myectomy
For hip dysplasia
Adductor of the hip
Inserts onto the capsule
Theory is that cutting this will reduce tension on the joint capsule (pain relief)
Does nothing to stabilise the hip or change sequelae
Clinical outcomes are very variable and it is not usually recommended
Juveline pubic symphiolysis
For hip dysplasia
Cauterise the symphis to stop growth
Triple pelvic osteotomy
For hip dysplasia
Reorientation of the pelvis to provide improved dorsal acetabular rim coverage
Was much more popular than it is now
Alternative approaches include DPO (double) and 2.5 DPO
Indications for triple pelvic osteotomy
Hip dysplasia but no secondary DJD
Clinically significant lameness and stiffness with attendant hip pain
Ideal candidate is 4-8 months of age, with positive Ortolani sign and clear “clunk” on reduction
Angle reduction / subluxation 25-35° / 5°-10°
Can be done as staged bilateral procedure
Procedure of triple pelvic osteotomy
3 cuts to mobilise the acetabular segment
Rotated around its longitudinal axis to increase dorsal rim cover
Ilial osteotomy is repaired with plate & screws
Strict exercise control until fracture planes have healed (4-6 weeks)
Outocmes of triple pelvic osteotomy
90% success
Complications can be serious, including screw pull-out or breakage
Procedure is relatively less common than it used to be
Intertrochaneteric osteotomy
Reorientation of the proximal femur to improve seating of the head within the acetabulum
Indicated in dogs with coxa valga and high femoral neck angle
Bone wedge is resected and the bone stabilised with plate and screws
Ostectomies
Remove diseased bone and joint
Femoral head and neck excision
Femoral head and neck excision
Salvage procedure, rarely first choice
□ Removes hip joint, leaving pseudarthrosis
□ Suboptimal ROM, hip stability and weight-bearing (but may not be clinically evident)
Can be used in any dog or cat with end-stage DJD
Straightforward procedure but some steps are critical to success
One of the few surgical procedures where we require early active mobilisation (rehab)
Not pain free after surgery
Active rehab is really important
Arthroplasty
Joint replacement
Does well for all cases
Total hip replacement
Total hip replacement
Restores hip function and should provide good stability and ROM
Can be used in dogs or cats with end stage DJD or pelvic/femoral neck fractures that cannot be repaired
Complex and expensive procedure, with potentially significant complications
Indications of total hip replacement
Coxofemoral arthritis (hip DJD)
Hip dysplasia
Chronic hip dislocation (luxation)
Fractured femoral head
Significant clinical hip dysfunction
Clinical outcomes of total hip replacement
Good to excellent outcomes in >90% cases
Major complications include luxation, femoral fracture, aseptic loosening, sepsis
Revision surgery is feasible (but expensive), as is conversion to excision arthroplasty
