AFC Arthritis Flashcards
Where do bones grow from?
Growth plate (epiphyseal plate)
State Hueter-Volkmann’s Law
Increased compression at the growth plate slows longitudinal growth
Increased tension at the growth plate speeds up longitudinal growth
Give an example of where Hueter-Volkmann’s Law can be used to correct an abnormality.
8 Growth Plate – if abnormal growth on 1 side of the distal tibial physis, insert a metal plate with pins on either side of the growth plate to prevent further growth on normal side + allow the other side to catch up
What are the three different types of knee alignment?
Normal/Neutral
Varus – bowed legs, weight bearing on medial knee
Valgus – knocked knees, weight bearing on lateral knee
What types of athletes get varus alignment?
Which part of the knee joint would be loaded most? What are the consequences of this?
Footballers
Medial surface
Wears out the cartilage + causes osteoarthritis
What surgical intervention can be performed before the onset of osteoarthritis to realign the knee joint?
Osteotomy: cutting the tibia to realign the knee joint
State Wolff’s Law.
Who does this effect?
Give an example that illustrates Wolff’s law.
Bone in a healthy person will adapt to the loads under which it is placed
Effects kids + adults
Surfer’s knots
What are the two surfaces of the cortical bone?
Periosteal surface (outer) Endosteal surface. (lining)
Load on the bones causes an increase in cortical thickness – how is this response to loading different in children compared to adults?
Children: have an active periosteum + endosteum so get increased bone growth at BOTH surfaces
Adults: periosteum is less active – so response to increased loading is mainly at endosteal surface
A lot of problems to do with body shape occur in utero. Give an example of such a problem that is associated with osteoarthritis and 3 associated risk factors
Developmental Dysplasia of the Hip (DDH)
Breech presentation
Female sex
Infant positioning in 1st year of life
Describe the appearance of the hip joint in someone who had DDH.
Hip joint may be higher than normal
Acetabulum is shallow + doesn’t cover much of the femoral head
Leads to increased load + wear
Why is it important to spot the deformities of DDH early?
If caught early, can realign + cause a remodelling of the joint to allow normal stance
Name and describe two abnormalities of the hip joint.
Cam – bump on the femoral neck
Pincer – extra bone makes acetabulum much deeper than normal
What are the negative consequences of Cam abnormality?
Deep flexion causes repeated impact between the bump on the femoral neck + acetabular rim leading to the wearing away of cartilage + osteoarthritis
What are the negative consequences of Pincer abnormality?
Femoral neck impinges + crushes the labrum causing labral tears + levers the femoral head into the postero-inferior acetabulum leading to a contrecoup cartilaginous injury
