Epiphysitis and Osteochondritis

Question 1

What is epiphysitis

Answer 1

the inflammation of bone ends (also called apohysitis/physitis)
it is a generalised bone disease characterised by the enlargement of growth plates in long bones
Apophysitis= separation of growth area by transverse forces and separation from large tendon forces

Question 2

What is osteochondritis

Answer 2

chondro=cartilage
A joint disorder in which, cracks form in the AC and the underlying subchondral bone, causing pain and swelling of affected joint
Joint condition in which a piece of cartilage and the thin layer beneath it separates from the end of the bone

Question 3

What is Osgoos-schlatters disease

Answer 3

condiditon in which the patella tendon pulls a bit off the tibial tuberosity and separates (tibial tuberosity sticks out)

Question 4

What is sever disease

Answer 4

calcaneal apophysitis (inflammation of the growth plate of the heel) affects achilles tendon

Question 5

What is Perthes’ disease

Answer 5

blood supply to the femur head is temporarily disrupted hence inadequate blood supply causing avascular necrosis and ‘flattening of femur head’
little kids get it most

Question 6

What is the epiphyseal plate

Answer 6

Area of bone for bone growth

Present from birth to puberty–> increased bone length

Question 7

How does bone growth at epiphyseal plate occur

Answer 7

proliferation of cartilage cells occurs (chondrocytes)
Chondrocyte columns grown away from the epiphyseal plate
chondrocytes mature and die and are surrounded my mineralised matrix
Making the bone longer

Question 8

What controls the rate of bone production

Answer 8

Hormones influence ‘balance’ between production and maturation
Puberty changes hormonal influences to maturation

Question 9

When are the epiphyseal plates ‘working’

Answer 9

Epiphyseal plates are in a constant process of production, maturation and mineralisation

Question 10

Why is the epiphyseal plate not present/not distinct in adults

Answer 10

Puberty (hence change in hormones) causes the epiphyseal plate to calcify and the epiphysis and metaphysis to merge–> decreasing bone growth

Question 11

What are the 4 zones of epiphyseal plate

Answer 11

Zone of resting cartilage
Zone of proliferating cartilage
Zone of hypertrophic cartilage
Zone of calcified cartilage

Question 12

What is the zone of resting cartilage in epiphyseal plate

Answer 12

nearest to epiphysis
consists of small, scattered chondrocytes
cells do not function in bone growth
anchor the epiphyseal plate to epiphysis

Question 13

What is the zone of proliferating cartilage in epiphyseal plate

Answer 13

Slightly larger chondrocytes, arranged like ‘stacks of coins’
chondrocytes undergo interstitial growth as they divide and secrete extracellular matrix
chondrocytes divide and replace those that die as diaphyseal side of epiphyseal plate

Question 14

What is the zone of hypertrophic cartilage in epiphyseal plate

Answer 14

consists of large, maturing chondrocytes arranged in columns

Question 15

What is the zone of calcified cartilage in epiphyseal plate

Answer 15

Only a few cells thick
Consists mostly of cartilage that are dead due to matrix around being calcified
Osteoclasts dissolve the calcified cartilage and osteoblasts and capillaries from the diaphysis invade the area
Osteoblasts lay down bone matrix, replacing calcified cartilage by the process of endochondral ossification

Question 16

What hormones promote bone proliferation

Answer 16

Insuline growth hormone
Growth hormone
Androgens (male sex hormone)

Question 17

What hormones promote epiphyseal fusion

Answer 17

Thyroid hormone deficiency

Oestrogen

Question 18

How does trauma affect epiphyseal plates

Answer 18

Trauma–> # involving plate= decreased blood supply to cartilage produces decreased bone length
excess exercise results in partial avulsion
Avulsion of epiphyseal plates

Question 19

How to infections anf tumours affect epiphyseal plates

Answer 19

Tumour–> epiphyseal plate is where new bone is forming hence higher risk of tumour
Infection–> increased vascularity to spiphyseal plate (due to body fighting off infection), which produces swollen epiphyseal plate and increases bone length

Question 20

What upsets epiphyseal plate

Answer 20

Endocrine disorders/hormones–> because it affects growth plate
Deformity to epiphyseal plate changes growth pattern, which changes joint biomechanics and predisposes it to more pathologies

Question 21

How does diet influence epiphyseal plates

Answer 21

Lack of folate causes spina bifida
Diet also influences mineralization
Starvation/illness slows cartilage proliferation but maturation continues= arrested growth (don’t grow as tall)

Question 22

What is the effect of forces on epiphyseal plates

Answer 22

Transverse and distraction forces produce dislocation fractures
Joint capsule and ligaments about epiphysis therefore stabilise epiphysis
But diaphysis translates
Epiphyseal plate is the weakest point hence displacement between epiphysis and disphysis
Affects children and adolscents, very rarely adults

Question 23

Where is epiphysitis common

Answer 23

long bones–> radial, ulna, humerus, femur. tibia