Hip and elbow dysplasia Flashcards
What is the difference between hip dysplasia and laxity
Hip dysplasia is a developmental hereditary condition but these puppies are normal at birth
Laxity in hips can be common in puppies and doesn’t predict later dysplastic changes
What breeds are assocaited with hip dysplasia
Labradors, GSDs, Rottweilers, Golden retrivers
+ crosses of thisW
What is a typical age of presentation for hip dysplasia
6-7 months
+ there is a second group that presents later on due to secondary degenerative joint disease as a result of hip dysplasia
What do we see on ortho exam of an animal with hip dysplasia
Asymmetric muscle mass over quads and glueals
Sensitivity over hind quarters
Pain on hip extension and abduction
Reduced range of motion
If crepitus is present, suggests DJD secondary to hip dysplasia
Asymmetric pad wear
Gait changes with hip dysplasia
Shortened low stride on (more) affected limb
Lateral sway
Bunny hopping if bilaterally affected
What is a psoas injury
Soft tissue injury of ileo-psoas muscle on medial side of the hip
Which dogs typically get avascular necrosis of the femoral head (Ddx for hip dyspasia)
Young small breed dogs
What are the two hip specific ortho tests
Ortolani test
Barden hip lift
What is a positive barlow sign
Subluxation in the Ortolani test
What is a positive ortolani sign
Reduction on abduction of the hip in Ortolani test
How does the ortalani test work
Dog heavily sedated/GI in dorsal recumbency
Push down on femur and feel it subluxate if loose in socket
Then abduct the femur until it reduces back into place (+ve ortalani sign)
Can then adduct hip to detect sublixation (positive Barlow)
What position is a dog in for the Barden test
Lateral recumbency
move femur up and down to detect movement (laxity)
What views is done for BVA hip scoring
VD extended view
What direction do subluxations of the hip tend to go and how can we tell
Cranio-dorsally or caudo-ventrally
Can tell using 2 radiographic views
What dorsal acetabular cover is normal
At least 50% of the femoral head being covered by the dorsal acetabular rim
What is the Norberg angle and what is normal
THe angle formed between the centre of the femoral head and the dorsal acetabular ring
Should be >105*; less suggests subluxation
What is Pennhip distraction index
Measuring of assessing risk of hip dysplasia by taking two radiographs with calibrated force applied to distract the hip between
- The less it moves, the tighter in the socker
> 0.7 distraction index associated with poor prognosis (0.3 good)
What is the painful part of hip dysplasia
Hip arthritis that develops later
What forms part of the conservative management of a dog with hip dysplasia
Rest, diet control esp if overweight
Controlled exercise; consistent small amounts of exercise
Rehab
Neutraceuticals/chondroprotectants in early stages
NSAIDs e.g meloxicam
Analgesia e.g paracetamol
Anti-NGF i.e librela
Quick summary of surgical options for hip dysplasia
Pectineal myectomy
Juveline pubic symphiolyss
Triple pelvic osteotomy
Intertrochanteric osteotomy
femoral head/neck excision
Joint replacement (arthroplasty)
How does a triple pelvic osteotomy work
Make a triple fracture in the pelvis; cut through wing of ileum, pubis and isceum
Then can rotate the acetabular segment to increase dorsal rim cover of femur head
- Plate it and allow to heal
What are the indications for triple pelvic osteotomy
Young dog with hip dysplasia (4-8months)
+ve ortolani sign
No osteoarthritis present
What is an intertrochanteric osteotomy
Reorientation of the proximal femur to improve seating of head in acetabulum
What is a femoral head-neck excision
Salvage procedure to remove the hip joint and leave a pseudarthrosis
Gives suboptimal range of motion etc; not pain free
Used in end stage degenerative joint disease
In which dogs can femoral head/neck exicsion be a problem
Larger dogs since get one leg shorter than the other
Which is the only surgery for hip dysplasia that requires early active mobilisation
Femoral head/neck excision
Otherwise get fibrosis and lack of mobility
What are some possible complications of hip replacement
Luxation
Femoral fracture
ASeptic loosening
Sepsis
May need revision surgery
Can convert to excision arthroplasty
What surgery gives most predictable and best clinical outcomes for hip dysplasia
Total hip replacement
Esp for large dogs since FHE less good
How does a pectineal myectomy work
Theory is cutting through pectineum muscle which is a hip adductor will reduce tension on the joint capsule (of hip) and reduce pain
NB: doesn’t stabilise the hip
What are the primary lesions of elbow dysplasia
Osteochondrosis of the humeral condyle
Ununited anconeal process
Fragmented medial coronoid process
Radio-ulnar incongruity
Which animals are typically affected by elbow dysplaisa
Large and giant breed dogs e.g labs, rottweilers
Also smaller chondrodystrophic breeds
Males 2X more common
Generally diagnosed between 6-12 months (again secondary peak of presentation where there is secondary osteoarthritis)
Clinical signs of elbow dysplaisa
- Forelimb lameness
- Shortened forelimb gait
- Commonly bilateral, but often asymmetric
- Effusion
- Pain +/- crepitus, reduced ROM
Which primary lesion of elbow dysplasia is radiography good at diagnosing and which view
ununited anconeal process; need flexed view
Which animals do we tend to see ununited anconeal processes in
GSDs, bernese mountain dogs, wolfhounds
How to deal with uninited anconeal process
If not much adaptive remodelling has happened yet can screw on to reattach
If there has been, remove the fragment
What additional thing can be done in surgery for screwing on the anconeal process to protect the screw from forces acting on it
Ulnar ostectomy to remove a portion
Or osteotomy to cut it
Why is the olecranon a tension site
Due to insertion of triceps
When does the growth plate at the anconeal process close normally
by 5 months
Which animals do we tend to see fragmented coronoid processes in
Labs, GSDs, bernese mountain dogs
Typically 6-14 months
What is the theory between fragmented coronoid processes
Microfracture due to contact between coronoid process and proximal radius leads to remodelling with brittle bone which cleaves off eventually to leave. af ragment
Treating fragmented coronoid processes
Can arthroscopically remove the fragment but it is not clearly better than conservative care
What consequence do we get from fragmented coronoid processes
Elbow DJD
When might fragment removal in fragmented coronoid process be more indicated
Where there is a clear separate body in the joint and the dog is variably lame i.e from the fragment moving
How do osteochondrosis lesions in the elbow work
Get a failure of endochondral ossification causing divet in medial humeral condyle
This cartilage is not intact so subsurface failure occurs and the cartilage flap lifts up to make dissecans lesion
What is an osteochondrosis dissecans lesion
Where abnormal cartilage lifts up to form a flap in the joint
What are some surgical options for elbow osteochondrosis
Arthroscopic debridement +/- graft
Osteochondral transplant using healthy core of subchondral bone and artiluar cartilage from the femur
- Then core out lesion and replace
Elbow joint replacement for widespread disease
Elbow arthrodesis as a salvage procedure to relieve pain as alternative to amputation
How does arthroscopic debridement in osteochondrosis lesion work
Lesion is hammered at to remove the diseased subchondral bone and cause bleeding from the bone marrow; this will form a clot which hardens into fibrocartilage
What is generally the cause of radio-ulnar incongruity
Short radius
Better diagnosed on CT
Don’t worry in young dogs
How is elbow incongruity treated
Ulnar osteotomy to allow ulnar to find a new posiiton
What views are taken for elbow dysplasia scoring
2 x mediolateral views
Flexed view 45* (good for looking at anconeal process)
Extended view 110*
Grade = highest grade
