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Flashcards in Pagets disease of the bone Deck (59)
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1
Q

what is Paget’s disease of the bone?

A

degenerative bone disease
disorder of bone metabolism
increased rate of bone remodelling at localised sites

2
Q

how common is it?

A

second most common degenerative bone disorder after osteoporosis

3
Q

how many people does it affect?

A

> 5% of over 55s in UK
prevalence varies between countries and races
unusual geographic distribution

4
Q

where is there high incidence ?

A

australia
new zealand
north america

5
Q

risk factors

A

male>female
increased incidence in pet owners
genetic susceptibility - increased risk in family history of disease
disease occurs in local geographical clusters

6
Q

causes

A

environmental factors in a predisposed individual
viral infection
incidence increases with age

7
Q

clinical features

A

chronic progressive
often asymptomatic
discovered incidentally with raised ALP of on x-ray
15-20% have symptoms

8
Q

symptoms

A
bone pain
bony deformity - warm skin overlying the lesion due to increased blood flow 
osteoarthritis 
fractures - due to brittle bones 
deafness
headaches 
non-specific neurological features such as dizziness 
osteosarcoma 
bowing deformity
9
Q

bone pain

A

late feature
deep constant aching pain
worse with weight bearing
persists through night

10
Q

common sites affected

A
pelvis 
lumbar spine
femur
thoracic spine
sacrum 
skull 
tibia
humerus
11
Q

what causes deafness/headaches?

A

compression of vestibulocochlear nerve when skull is affected

12
Q

what is an osteosarcoma?

A

primary bone cancer

13
Q

what is bowing deformity?

A

altered gait
joint pain - hips and lower back
when long bones are affected

14
Q

pathology

A

increased number of osteoclasts which are larger
osteoblasts are normal and overactive due to increased factors released by osteoclasts
osteoclasts oversensitive to vitamin D
accelerated rate of bone turnover and subsequent rapid new bone formation with a disorganised matrix

15
Q

what happens to bones?

A

increased size
more brittle
more prone to fracture

16
Q

investigations required

A
bloods 
x-rays 
radionuclide bone scan 
bone biopsy 
CT/MRI to better define unusual bone lesions
17
Q

blood tests

A
ALP - bone-sepcific 
GGT 
serum calcium 
serum phoshate 
vitamin D
18
Q

ALP/Alk P

A

indicator of osteoblastic activity

raised

19
Q

GGT

A

to rule out liver cause if ALP is raised and bone-specific ALP cannot be tested

20
Q

severity of disease

A

correlated with ALP

21
Q

serum calcium and phosphates

A

normal

abnormal may indicate parathyroid disease rather than other pagets disease

22
Q

vitamin D

A

can be used to rule out another cause of raised ALP

to ensure levels are sufficient to undertake bisphosphonate therapy

23
Q

x-ray findings

A
widening of cortical region 
mixed areas of sclerosis and lysis 
bone thickening and enlargement 
bone deformities 
localised osteoporosis in areas of very high osteoclast activity - osteoporosis circumscripta
24
Q

widening of cortical region

A

hollow cortex at centre of bone is wider

25
Q

mixed areas of sclerosis and lysis

A

lots of opaque dark splodges in bone

seen in early disease

26
Q

bone thickening and enlargement

A

seen in later disease

easier to differentiate

27
Q

bone deformities

A

bone bends anteriorly in tibia and bone bends laterally in femur

28
Q

bone scan

A

increased isotope uptake in affected bones
often performed after initial lesions have been diagnosed to assess the extent of disease
any areas that show uptake on bone scan should be further investigated with x-ray to confirm paget’s disease

29
Q

urine

A

may contain collagen due to very high bone resorption

30
Q

differentials

A

bone malignancy
osteoarthritis
osteoporosis

31
Q

treatment aims

A

reduce pain

slow down rate of bone remodelling

32
Q

deciding who to treat

A

based on symptom severity

asymptomatic disease not often treated

33
Q

who to treat?

A

severe pain
nerve compression from expanding bone or neurological complications
fractures
asymptomatic disease with significant biochemical abnormalities

34
Q

abnormal biochemistry that requires treatment

A

ALP >2 x normal

raised ALP and paget disease at a site that commonly results in fracture

35
Q

what is the treatment?

A

bisphosphonates

36
Q

how do bisphosphonates work?

A

inhibit osteoclast activity and cause osteoclast apoptosis

damage cytoskeleton of osteoclast so the cells is unable to bind to bone and unable to do bone resorption

37
Q

pre-treatment checks

A

serum calcium and vitamin D

start patients on supplemental vitamin S and calcium

38
Q

length of treatment

A

often able to induce remission

typically treated for 2 months

39
Q

what type of bisphosphonates are used?

A

newer/ nitrogen containing bisphosphonates

40
Q

what bisphosphonates can be used?

A

zolendronic acid
pamidronate
risedronate/alendronate - oral

41
Q

what can be used for those that cannot tolerate bisphosphonates?

A

calcitonin

42
Q

zolendronic acid

A

IV infusion - 5mg over 15 mins

resistance can develop

43
Q

side effects of zolendronic acid

A

can cause flu-like symptoms after first dose

44
Q

what to use when there is resistance developed to zolendronic acid?

A

pamidronate

45
Q

pamidronate

A

IV older bisphosphonate

46
Q

oral bisphosphonate therapies

A

risedronate

alendronate

47
Q

when to use oral bisphosphonates?

A

younger patients

less severe disease

48
Q

risedronate dose

A

30mg for 2 months daily

49
Q

alendronate dose

A

40mg daily for 3-6 months

50
Q

cautions when taking oral bisphosphonates

A

take with water
no food for 30 mins after
don’t lie down for 2 hours after to avoid oesophageal irritation and gastroesophageal reflux
dental work needs to be done before initiating therapy as it increases risk of osteonecrosis of jaw

51
Q

calcitonin

A

doesn’t induce remission but can reduce disease progression

52
Q

adverse effects of bisphosphonates

A

osteonecrosis of jaw
bone pain
flu-like symptoms

53
Q

other management options

A
simple analgesia 
orthoses
orthotics
education 
treat complications
54
Q

orthoses

A

braces for support and protection

55
Q

orthotics

A

shoe inserts

help correct deformity and altered gait

56
Q

treating complications

A

joint replacement
hearing aids
physio

57
Q

ongoing management

A

consider repeating ALP at 3-6 months to assess efficacy of treatment
repeat ALP annually
initiate treatment again when ALP starts to rise or patient becomes symptomatic again

58
Q

complications

A

increased risk of bone tumours - osteosarcoma

59
Q

osteosarcoma

A

1% incidence of paget’s disease patients
consider this in lesions that do not respond to medical therapy - especially pain
often advanced and fatal
more common in people with long standing disease