Bone Disease Flashcards
Define osteoporosis
Decreased bone mass and micro-architectural deterioration leading to bone fragility and increased risk of fractures.
how far below healthy mean bone density is defined as osteoporosis?
2.5 standard deviations below normal value
What causes osteoporosis?
Results from increased bone breakdown by osteoclasts and decreased bone formation by osteoblasts, leading to loss in bone mass.
Identify the four main causes of osteoporosis
genetic factors influencing bone mass
oestrogen deficiency
glucocorticoids
ageing
Identify 2 ways of preventing osteoporosis
diet including enough calcium and vitamin D
weight bearing exercise
Give 2 major causes of osteonecrosis (avascular necrosis)
glucocorticoid treatment
alcohol excess
What is Paget’s disease of bone? Give a brief explanation of the pathogenesis
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.
What is avascular necrosis?
necrosis of the bone due to insufficient blood supply
Identify several causes of Paget’s disease
Mutations of SQSTMI1
viral infection- paramyxovirus, RSV, measles
Identify some clinical features of Paget’s disease
60-80% asymptomatic skull enlargement Leontiasis ossea arthritis bowed legs bone pain, fractures, deformities cranial nerve compression
Where does Paget’s disease normally occur?
the axial skeleton
What is osteomalacia and what is rickets?
osteomalacia is defective mineralisation of newly formed bone matrix or osteoid.
Rickets is defective mineralisation of the epiphyseal growth plate in children
What is the most common cause of osteomalacia?
Vitamin D Deficiency which results in hyperparathyroidism and hypophosphataemia
What is osteomyelitis? In which age group is it most common?
Infection of the bone/bone marrow resulting in inflammation.
more common in children
How does Osteomyelitis arise?
the haematogenous spread of a pathogen to the vascular metaphysis
In adults osteomyelitis usually occurs in the setting of what two conditions?
Type 2 diabetes mellitus
chronic skin ulceration (direct spread not haematogenous)
What organism is the main cause of osteomyelitis? what other two organisms may cause Osteomyelitis?
staphylococcus
salmonella, H. influenzae
What is the classical presentation of Osteomyelitis?
fever
overlying tenderness
localised bone pain
erythema
What is the rough 3 classes of bone tumours?
Bone forming
cartilage forming
others
What is the most common primary bone tumour? Name three other types
Multiple myeloma
osteosarcoma
chondroma
Ewing’s sarcoma
Give 5 examples of the origin of secondary bone tumours
breast lung prostate kidney thyroid
Bone cancers are __________ cancers in adults and ________ in children. They are mostly idiopathic but what are the three main risk factors?
Rare
Common
radiotherapy
genetic- le Fraumeni (p53) and familial retinoblastoma
predisposing conditions- Pagets disease, fibrous dysplasia, enchondromas
Name some red flag symptoms of bone tumours
persistent, increasing pain
pain worse at night
red, hot swelling
palpable mass
Which five radiographic features do you examine to look investigate bone tumours?
Location neocortex zone of transition matrix cortical involvement
