Osteoporosis, Pagets, Osteogenesis Imperfecta

Question 1

What is osteoporosis?

Answer 1

systemic skeletal disease, characterised by low bone mass and microarchitetural deteriation of bone tissue which leads to increased bone fragility and susceptibilty to fracture

Question 2

What is the role of osteoclasts during bone remodelling?

Answer 2

reabsorb the bone

Question 3

What is the role of osteoblasts during bone remodelling?

Answer 3

replace the cavity formed by the osteoclasts by laying down osteoid that is then mineralised to new bone

Question 4

What is required for normal bone turnover?

Answer 4

complete balance between osteoclasts and osteoblasts

Question 5

What is the bone turnover situation in osteoporosis?

Answer 5

more osteoclasts than osteoblasts

Question 6

What factors can cause bone loss?

Answer 6

sex hormone deficiency
genetics
body weight
immobility
glucocorticoids
aromatase inhibitors

Question 7

How is bone density assessed?

Answer 7

DEXA bone scan measures the BMD (fracture risk)

Question 8

What is does a high T score indicate?

Answer 8

high fracture risk

Question 9

How is osteoporosis diagnosed by BMD?

Answer 9

> 2.5 SDs below the young adult mean

Question 10

How is osteomalacia diagnosed by BMD?

Answer 10

> 1 SD below the young adult mean

Question 11

What does a low BMD indicate?

Answer 11

low fracture risk

Question 12

What is the non pharmacological treatment for osteoporosis?

Answer 12

change modifyable factors eg alcohol, smoking, physical inactivity
high intensity muscle training
low impact weight bearing exercise
700mg calcium daily

Question 13

What is the pharmacological treatment for osteoporosis?

Answer 13

calcium and vit D supplements
Biphosphonates - anti reabsorptive agents (ingested by osteoclasts leading to their cell death)
Zoledronic Acid - IV infusion
Denosumab - monoclonal antibody - inhibits activity of osteoclasts
Teriparaticle - recombinant parathyroid hormone that stimulates bone growth

Question 14

What is Pagets disease?

Answer 14

abnormal osteolastic activity that is then followed by abnormal osteoblastic activtiy leading to an abnormal bone strength

Question 15

What is wrong with the bone in pagets disease?

Answer 15

there is an increased fracture risk

reduced strength

Question 16

What bones are normally affected by pagets disease?

Answer 16

long bones
pelvis
lumbar spine
skull - hearing loss

Question 17

What is the age normally affected by pagets?

Answer 17

> 40

Question 18

How does pagets present?

Answer 18

bone pain
deformity
deafness
compression neuropathy

Question 19

How is pagets diagnosed?

Answer 19

X ray
isolated bloos All phos
isotope bone scan will show the disease distribution

Question 20

How is pagets treated?

Answer 20

analgesia for pain

biphosphonates

Question 21

What are the genes that are mutated in Osteogenesis imperfecta?

Answer 21

AUTOSOMAL DOMINANT

secondary to mutations of type 1 collagen genes (COLLA1, COLLA2)

Question 22

What are type 1-4 of Osteogenesis imperfecta?

Answer 22

1: mild
2: neonatal - lethal
3 and 4: very severe - most common

Question 23

How does Osteogenesis imperfecta present?

Answer 23

most severe -> fractures in childhood
mild form -> fractures in adulthood
blue scelrae and detinogenesis imperfecta (discoloured teeth)

Question 24

What is the treatment for Osteogenesis imperfecta?

Answer 24

fracture fixation
surgery to perfect deformities
biphosponates
NO CURE