Bone Disease

Question 1

Define osteoporosis

Answer 1

Decreased bone mass and micro-architectural deterioration leading to bone fragility and increased risk of fractures.

Question 2

how far below healthy mean bone density is defined as osteoporosis?

Answer 2

2.5 standard deviations below normal value

Question 3

What causes osteoporosis?

Answer 3

Results from increased bone breakdown by osteoclasts and decreased bone formation by osteoblasts, leading to loss in bone mass.

Question 4

Identify the four main causes of osteoporosis

Answer 4

genetic factors influencing bone mass
oestrogen deficiency
glucocorticoids
ageing

Question 5

Identify 2 ways of preventing osteoporosis

Answer 5

diet including enough calcium and vitamin D

weight bearing exercise

Question 6

Give 2 major causes of osteonecrosis (avascular necrosis)

Answer 6

glucocorticoid treatment

alcohol excess

Question 7

What is Paget’s disease of bone? Give a brief explanation of the pathogenesis

Answer 7

it is a disorder of bone remodelling. With this disease bone formation exceeds bone resorption by osteoclasts.the new woven bone is weaker than normal bone and leads to deformity and increased risk of fractures.

Question 8

What is avascular necrosis?

Answer 8

necrosis of the bone due to insufficient blood supply

Question 9

Identify several causes of Paget’s disease

Answer 9

Mutations of SQSTMI1

viral infection- paramyxovirus, RSV, measles

Question 10

Identify some clinical features of Paget’s disease

Answer 10

60-80% asymptomatic
skull enlargement
Leontiasis ossea
arthritis
bowed legs
bone pain, fractures, deformities
cranial nerve compression

Question 11

Where does Paget’s disease normally occur?

Answer 11

the axial skeleton

Question 12

What is osteomalacia and what is rickets?

Answer 12

osteomalacia is defective mineralisation of newly formed bone matrix or osteoid.
Rickets is defective mineralisation of the epiphyseal growth plate in children

Question 13

What is the most common cause of osteomalacia?

Answer 13

Vitamin D Deficiency which results in hyperparathyroidism and hypophosphataemia

Question 14

What is osteomyelitis? In which age group is it most common?

Answer 14

Infection of the bone/bone marrow resulting in inflammation.

more common in children

Question 15

How does Osteomyelitis arise?

Answer 15

the haematogenous spread of a pathogen to the vascular metaphysis

Question 16

In adults osteomyelitis usually occurs in the setting of what two conditions?

Answer 16

Type 2 diabetes mellitus

chronic skin ulceration (direct spread not haematogenous)

Question 17

What organism is the main cause of osteomyelitis? what other two organisms may cause Osteomyelitis?

Answer 17

staphylococcus

salmonella, H. influenzae

Question 18

What is the classical presentation of Osteomyelitis?

Answer 18

fever
overlying tenderness
localised bone pain
erythema

Question 19

What is the rough 3 classes of bone tumours?

Answer 19

Bone forming
cartilage forming
others

Question 20

What is the most common primary bone tumour? Name three other types

Answer 20

Multiple myeloma
osteosarcoma
chondroma
Ewing’s sarcoma

Question 21

Give 5 examples of the origin of secondary bone tumours

Answer 21

breast 
lung
prostate
kidney 
thyroid

Question 22

Bone cancers are __________ cancers in adults and ________ in children. They are mostly idiopathic but what are the three main risk factors?

Answer 22

Rare
Common
radiotherapy
genetic- le Fraumeni (p53) and familial retinoblastoma
predisposing conditions- Pagets disease, fibrous dysplasia, enchondromas

Question 23

Name some red flag symptoms of bone tumours

Answer 23

persistent, increasing pain
pain worse at night
red, hot swelling
palpable mass

Question 24

Which five radiographic features do you examine to look investigate bone tumours?

Answer 24

Location
neocortex
zone of transition
matrix
cortical involvement