Paget's disease of bone

Question 1

Define Paget’s disease of bone

Answer 1

Characterised by excessive bone remodelling at 1 (monostotic) or more (polyostotic) sites resulting in bone that is structurally disorganised

Question 2

Aetiology of Paget’s disease of bone

4

Answer 2

UNKNOWN
Genetic factors & viral infection may play a role
Excessive bone resorption by abnormally large osteoclasts is followed by increased bone formation by osteoblasts in a disorganised fashion —> abnormal pattern of lamellar bone
Marrow spaces are filled by an excess of fibrous tissue w/ a marked increase in blood vessels

Question 3

Epidemiology of Paget’s disease of bone

agex2, gender

Answer 3

Common in ELDERLY
3% of >50 yr olds, 10% of >80 yr olds
Males = females

Question 4

Presenting symptoms of Paget’s disease of bone

5

Answer 4

May be ASYMPTOMATIC
May present with insidious onset pain, which is aggravated by weight bearing & movement 
Headaches
Deafness
Increasing skull size

Question 5

Signs of Paget’s disease of bone on physical examination

5

Answer 5

Bitemporal skull enlargement w/ frontal bossing (prominent, protruding forehead)
Spinal kyphosis
Anterolateral bowing of femur, tibia or forearm
Skin over affected bone may be warm (due to increased vascularity)
Sensorineural deafness (due to compression of vestibulocochlear nerve)

Question 6

Investigations for Paget’s disease of bone

4 groups

Answer 6

Bloods
Bone radiographs
Bone scan
Resorption markers

Question 7

Investigations for Paget’s disease of bone - bloods

2

Answer 7

High ALP

Ca2+ & phosphate NORMAL

Question 8

Investigations for Paget’s disease of bone - bone radiographs
(4)

Answer 8

Enlarged, deformed bones
Lytic & sclerotic appearance
Lack of distinction between cortex & medulla
Skull changes:
osteoporosis circumscripta
enlargement of frontal & occipital areas
cotton wool appearance

Question 9

Investigations for Paget’s disease of bone - bone scan

2

Answer 9

Assesses extent of skeletal involvement

Pagetic bone lesions appear as areas w/ markedly increased uptake

Question 10

Investigations for Paget’s disease of bone - resorption markers
(2)

Answer 10

Monitors disease activity

Check urinary hydroxyproline