SA Hindlimb Flashcards
What are the d/dx for hip joint pathology?
- Hip Joint
- hip dysplasia
- Perthes disease
- osteoarthritis
- luxation
- fractures of proximal femur or pelvis
- muscle strains ( uncommon)
What is canine hip dysplasia determined by?
animals genes
At birth how do dogs genetically predisposed to hip dysplasia hips appear macroscopically?
Dogs genetically predisposed to HD have macroscopically normal hips at birth, but changes begin within a few weeks
What promotes phenotypic expression of HD?
rapid growth and abundant food promote phenotypic expression of the HD
Describe the bimodal age distribution of HD?
Bimodal age distribution of clinically affected dogs:
3-12 months: synovitis
2-12+ years: osteoarthritis
Create a flow chart for the pathogenesis of hip dysplasia?
What are the clinical signs of hip dyslpasia?
May be asymptomatic
May be non-specific: tires, doesn’t play, stiff on rising, reluctant to jump
Observe:
- stiffness on rising
- may stand shifting weight onto front legs
- bilateral or unilateral hindlimb lameness: may wiggle, cross legs or bunny hop
Palpate:
- hindquarter muscle atrophy, particularly gluteals
Manipulate hips:
- pain esp. on extension and abduction
- decreased range of motion or joint instability ± crepitus
- Ortolani sign
What is joint laxity dependent on?
Hip Laxity Joint laxity is dependent upon:
- joint capsule thickness
- integrity of ligament of femoral head
- integrity of dorsal acetabular rim and muscle tension
- Surface tension in the synovial joint
How can hip laxity be assessed?
- Barden ’ s Palpation (hip lift)
- Barlow’s Sign
- Ortolani Test (sedation / GA)
What is the ortolani test?
- Pressing down on the femur see a subluxation of hip (angle of subluxation) then as you abduct the hip it should pop back in (Angel of reduction)
- Best indication of a degree of instability
A positive sign is a distinctive ‘clunk’ which can be heard and felt as the femoral head relocates anteriorly into the acetabulum
How is radiography done for hip dysplasia?
- Ventrodorsal extended femur view - must be straight
- Lateral pelvis / LS junction ( ± flexed)
- Frog leg view Radiography (beware though can give a false impression that hips sit better than they do in reality in this view)
How can we assess level of hip sub/luxation from radiographic images?
Want to look at dorsal acetabular rim: yellow squiggly line
The red dot on the femoral head should sit where the left red dot is in a non luxated hip.
Dorsal lateral acetabular ridge: White curve line looking at wear and tear on it
New bone: Yellow arrows. New bone seen in dorsal, ventral aspects of acetabulam and around the femoral head. A good indication joint is unhappy and under a degree of strain.
50% coverage of the femoral head is correct as seen in image
What is the distraction index?
NOT appropriate for UK due to requirement to hold animal during radiography
0 = perfect congruity
0.3 -0.7 = abnormal
1 = complete luxation
Describe conservative management for hip dysplasia?
Treatment Conservative management should always be tried first:
- weight control
- regular exercise to build muscle (especially the gluteals)
- physiotherapy and hydrotherapy
- strategic analgesia (5-7 days as and when needed)
- +/-nutraceuticals
The majority ( 76% ) of juvenile dogs with severe radiographic signs of hip dysplasia may be only mildly clinically affected in later life if they are properly managed: kept at optimal weight and regularly exercised
What are the treatments for hip dysplasia?
Immature dog:
- pectineus myotomy / myectomy
- Triple/double pelvic osteotomy
- femoral neck lengthening
- DARthroplasty
- femoral head and neck excision
- pubic symphysiodesis
Mature dog:
- femoral head and neck excision
- total hip replacement
When would a triple pelvic osteotomy be indicated in dogs?
Potential candidate would have:
- painful hip(s), non-responsive to analgesia
- unstable but reducible hips
- no / minimal remodelling or degenerative changes
so mainly immature dogs (5-10 months of age)
What is the theory of the triple pelvic osteotomy?
Acetabular segment rotated laterally to capture femoral head –> stabilise hip –> clinical improvement and reduced DJD
Theoretically, degree of rotation determined from Ortolani angles (20, 30, 40 degree plates)
Bilateral surgery if appropriate -staged
What is occuring here?
- Perthes disease –avascular necrosis of the femoral head
- Seen usually in small breed dogs, usually 3-13 months old
- Multifactorial aetiology (Manchester Terriers- highly heritable)
What are the clinical signs of perthes disease?
Clinically:
- progressive lameness
- hip pain
- muscle atrophy
- reduced hip ROM
- crepitation
Usually unilateral –bilateral in 12-16.5% cases
Non-inflammatory aseptic necrosis of the femoral head and neck
What are possible treatments for avascular necrosis of the femoral head?
Treatment –
- conservative (in his experience relatively unsuccessful)
- femoral head and neck excision
- total hip replacement
On a clinical exam of a suspected cranial cruciate ligament rupture what might be seen?
Palpate:
- may be some muscle atrophy of affected leg(s), particularly of the quadriceps muscles
- may feel stifle effusion
- may feel medial buttress (see pic)
Manipulate:
- painful on extension
- unstable?
List some of the causes of cranial cruciate ligament?
What can be seen in the yellow triangle?
Joint effusion shown by increased radio opacity
Look at some arthroscopy of cruciate ligaments?
When does a meniscal tear occur?
May be more painful / lame ±audible ‘ click ’
Presence of meniscal tear at time of CrCL rupture:
- partial ruptures: 5-25% occurs
- complete ruptures: reportedly up to 80%
Delayed / late meniscal injury after CrCL rupture:
- may be up to 14%
- usually caudal horn of medial meniscus
- caudal longitudinal tear (bucket-handle), and crushing of the caudal horn most common
- inner 2/3 rds avascular, so healing is poor –>requires (partial) meniscectomy
Dicuss canine patella luxation?
- Common condition 2 sets suffer: small terriers and larger dogs
- Caused by quadriceps / extensor mechanism mal-alignment
- If patella not in groove during development, groove remains shallow
- dogs may also have bony deformities of femur (varus) and tibia
- usually congenital but occasionally traumatic
How can patella luxation be graded?
Draw an image of block and wedge resection for canine patella luxation surgery?
How is a block recession done?
Show some pics of tibial crest transposition?
Discuss greyhound fractures?
Acute non-weightbearing lameness of right hind
Central tarsal bone –> collapse of hock –> fracture of 4 th tarsal, calcaneus and 5 th metatarsal bones
Treatment:
- surgical repair of fractures - refer
- partial arthrodesis
