B6.066 Paget Disease of the Bone

Question 1

sources of alk phos

Answer 1

bone
liver
placenta

Question 2

physiologic states associated with alk phos elevation

Answer 2

post prandial (more common w certain blood types)
pregnancy

Question 3

what can help determine the source of alk phos

Answer 3

GGT
5-nucleotidase
bone specific alk phos
bilirubin, LFTs

Question 4

GGT

Answer 4

elevation suggests cholestasis

Question 5

5-nucleotidase

Answer 5

elevation suggests cholestasis

Question 6

total bilirubin

Answer 6

elevation suggests liver path

Question 7

elevated bone alk phos

Answer 7

indicative of high bone turnover

marker of osteoblastic activity

Question 8

reasons bone alk phos may be elevated

Answer 8

pHPTH (high Ca)
thyrotoxicosis
osteomalacia (low vit D)
malignancy of the bone (primary vs metastatic)
Pagets

Question 9

diagnostic step for Pagets after isolating bone alk phos

Answer 9

xray

radionuclide bone scan

Question 10

xray findings in Pagets

Answer 10

bony overgrowth
thickened cortices marked by tunneling
accentuated trabeculae

Question 11

bone scan findings in Pagets

Answer 11

increased metabolic activity

Question 12

what is Pagets?

Answer 12

focal areas of increased and disorganized bone remodeling

• overactive osteoclastic bone resorption
• compensatory increase in osteoblastic new bone formation
  result: structurally disorganized mosaic of bone

Question 13

discuss the structure of bone in pagets

Answer 13

expanded
less compact
more vascular
more susceptible to fractures

Question 14

preferential targets of Pagets

Answer 14

axial skeleton:

1. pelvis
2. femur
3. lumbar spine
4. skull
5. tibia

Question 15

osteocytes

Answer 15

osteoblasts that remain within cortical bone
orchestrate remodeling process of bone
sensors of mechanical loading

Question 16

pagets epidemiology

Answer 16

rare before 55
5% of women, 8% of men by 8th decade of life
primarily Caucasian (rare in African, indian, Asian)
15% have positive family history

Question 17

inheritance of pagets

Answer 17

AD fashion

incomplete penetrance

Question 18

etiology of pagets

Answer 18

unknown

evidence for genetic and viral etiologies

Question 19

how does pagets present?

Answer 19

incidental finding on radiology testing
asymptomatic biochemical testing
up to 40% have bone pain

Question 20

how is paget diagnosed?

Answer 20

elevated alk phos, bone specific when fractionated
normal calcium
normal phos
normal PTH

Question 21

indication for therapy in pagets

Answer 21

symptoms from active disease
pagetic lesions involving weight bearing skeleton
metabolically active lesions
-bone turnover markers
-bone scan
potential consequence of bony overgrowth

Question 22

bisphosphonate side effects

Answer 22

upper GI irritation
severe musculoskeletal pain
hypocalcemia
uveitis / scleritis
osteonecrosis of the jaw
atypical femur fracture

Question 23

zolendronic acid

Answer 23

IV formulation, potent, infuses over 15 minutes
most sustained response
-biochemical remission after one dose may be years long

Question 24

oral bisphosphonate options for pagets

Answer 24

risedronate 30 mg once daily for 2 months

alendronate 40 mg daily for 6 months

Question 25

when are bisphosphonates contraindicated

Answer 25

kidney disease

use calcitonin

Question 26

goals of pagets therapy

Answer 26

ease bone pain

normalize rate of bone remodeling

Question 27

outcome measures of pagets therapy

Answer 27

normalization of alk phos (3-6 months)

avoid structurally disorganized mosaic of bone

Question 28

when to retreat pagets

Answer 28

recurrence of abnormal bone turnover

• serial alk phos measures
• radiographic progression
• recurrent pain