LEC 24 - SA Extremities Flashcards
What is the general rule for determining hip dysplasia?
50% rule - if the head of the femur is covered by 50% of the acetabulum
How can you tell in a hip xray whether or not it is straight?
Oburator foramen equal sizes
How are the two major positional goals in hip x-rays?
Patella over femoral condyle and femurs parallel
What abnormalities could occur at the coxofemoral joint?
Hip dysplasia, luxation, etc.
What side of the hips sees the highest occurence of luxation?
Left
What secondary changes do you see with hip dysplasia besides luxation?
Joint capusle laxity and femoral ligament stretch. Once chronic can cause DJD and osteoarthritis.
What is a common fracture that occurs at the femoral head?
Capital physeal fracture
Where is captial physeal fractures most commonly seen?
Young, male cats
What is the general appearance of a healthy stifle?
Fat pad present, joint capsule within joint, condyles should be superimposed, and patella should be a normal “D” shape
What is a salter-harris fracture?
Physis hasn’t closed yet. Fracture then occurs at this weak point of the bone. Prevents further growth of the bone.
How do fractures heal?
Callus develops from outside, in. Leads to secondary healing process.
How do you know the difference between secondary and primary bone healing?
No callus is formed with primary bone healing
What three places might a bone tumor occur that would suggest it is a primary bone tumor?
Proximal humerus, distal femur, and distal tibia
If bone lysis is noted on x-ray what are your two main differentials?
Cancer or infection
What is a sign something is a bone infection not cancer?
infections look more proliferative rather then destructive
What is most likely the cause of osteomyelitis in multiple regions?
Systemic infections
What does a bone cyst look like on x-ray?
Cortex thinning, nice neat capsule with distinct borders.
Where do secondary bone tumors begin?
At the nutrient foramen
What is a cancer that occurs in the joint capsule?
Synovial cell sarcoma
What is the radiographic description of Synovial cell sarcoma?
Will cross the joint on both sides
How do you know if something is synovial cell sarcoma rather then osteosarcoma?
OSA does not cross the joint while SCC does.
What is the general appearance of panosteitis on x-ray?
Will occur in a young dog. Medullary canal will appear to be more lucent
What are three common ways that you see elbow dyplasia?
UAP, Chronic DJD, and elbow incongruity
How might a dog present with elbow dysplasia?
Weight will be distributed more on the medial side.
Where do you first see changes in the elbow with elbow dysplasia?
Medial (ulnar notch) rather than lateral (radial head)
How much of bone growth does Ulnar physes account for?
85%
How much of bone growth occurs at each end of the bone?
50%/50%
What ligament is commonly torn when carpal luxation is seen on radiographs?
Palmar ligament
Describe Varus -
Deviates medially, increased lateral growth, decreased medial growth
Describe Valgus -
Deviates laterally, increased medial growth, decreased lateral growth
What causes legg-calve-perth’s disease?
Decrease blood flow to femur leading to bone atrophy
How might a dog present with a malunion fracture?
Not really that painful walk further up on toes
