Bone abnormalities

Question 1

What are the functions of bone?

Answer 1

Haematopoiesis
Metabolic tissue (mineral buffer, repair damage, quality of bone)
Protective, supportive,
load bearing

Question 2

If a normal bone is put under excessive force, what would happen?

Answer 2

Fracture

Question 3

If a weak bone was put under normal force, what would happen?

Answer 3

Fracture

Question 4

If a normal bone was put under normal force, what would happen?

Answer 4

Nothing! haha (no fracture

Question 5

What blood tests can be performed to assess bone structure?

Answer 5

alkaline phosphatase! (also used in liver) albumin
calcium, phosphate!
vitamin D, parathyroid hormone
U&Es (kidney disease causes abnormal mineral regulation
FBCs

Question 6

What imaging can be done to assess bone structure?

Answer 6

Plain X-ray

Radionuclide scans CT / MRI / ultrasound

Question 7

Apart from blood tests and imaging, what other methods are there to assess bone structure?

Answer 7

Bone biposy and bone density (DEXA scan)

Question 8

What is a DEXA scan?

Answer 8

Dual Energy X-Ray Absorptiometry (Block 4 week 2 CBL case)

Question 9

What are the two kind of problems you can get with bone abnormalities?

Answer 9

Quantity of bone:
Too little - osteoporosis
Too much - osteopetrosis

Quality of bone:
Defective - rickets, osteomalacia and hyperparathyroidism
Change in structure - osteogenesis imperfecta and paget;s disease

Question 10

How does parathyroid hormone (PTH) link to calcium levels and thus bone density.

Answer 10

Parathyroid glands secrete PTH. PTH regulates the level of calcium in the body. Calcium is needed to make bone.

Question 11

What is osteoporosis?

Answer 11

A complex skeletal disease characterised by low bone density and micro-archeitectural defects in bone tissue, resulting in increased bone fragility and susceptibility to fracture.

Question 12

What bones are most commonly fractured?

Answer 12

Vertebrae, femur and wrist

Question 13

What wider implications can osteoporosis have?

Answer 13

Future fractures
Quality of life
Pain
Long term admission
Mortality

Question 14

When is peak bone mass usually received?

Answer 14

around 30 years of age

Question 15

What factors contribute to getting peak bone mass?

Answer 15

Nutrition, physical activity and genetic factors

Question 16

How can menopause lead to osteoporosis?

Answer 16

Decreased serum oestrogen, increased IL-6/1, TNF levels, increased expression of RANK and RANKL, increased osteoclast activity

Question 17

How can ageing lead to osteoporosis?

Answer 17

Decreased replicator activity of osteoprogenitor cells, decreased synthetic activity of osteoblasts, reduced physical activity, decreased biologic activity of matrix bound growth factors

Question 18

Name some risk factors of osteoporosis

Answer 18

Old age, female, ethnicity, family history, low BMI, nutrition, vit D and calcium deficiency, steroids, post-menopausal, excessive alcohol

Question 19

In a DEXA scan, what does the T-score show?

Answer 19

T-score used to compare bone density of patient with that of the average of the people of that age.
T-score more than -1 - normal
less than -1 but above -2.5 is osteopenia
less than -2.5 is osteoporosis

Question 20

What type of pharmacological treatments are available for osteoporosis?

Answer 20

Bisphosphonates
SERM
PTH
Denosumab

Question 21

Name the first line treatment of Bisphosphonates for osteoporosis.

Answer 21

Alendronic acid

Question 22

What is the MoA of bisphosphonates?

Answer 22

Slows the rate of bone remodelling

Question 23

Name a SERM used for osteoporosis and its moa.

Answer 23

Raloxifene - moxed antagonist and agonist function (tissue specific)

Question 24

What are the side effects of SERMs?

Answer 24

Hot flushes, DVT and stroke

Question 25

How does PTH help in osteoporosis and how is it administered?

Answer 25

Promotes bone production by inhibition of release of calcium from bone. By a SC injection.

Question 26

What is denosumab and how does it work?

Answer 26

Denosumab is a monoclonal antibody, it works by inhibiting osteoclast formation, function and survival. Given by SC injection

Question 27

How are rickets and osteomalacia similar but different?

Answer 27

Different manifestations of same pathological process.
Rickets
Affects children
Defective mineralisation at the growth plate

Osteomalacia
Affects adults
Defective mineralisation of osteoid

Question 28

What is the most common cause of rickets and osteomalacia?

Answer 28

Vitamin D deficiency usually resulting in low calcium (and low phosphate) levels

Question 29

What is rickets?

Answer 29

Rickets is a condition that affects bone development in children. It causes bone pain, poor growth and soft, weak bones that can lead to bone deformities.
GROWTH RETARDATION
BONY DEFORMITIES

Question 30

Describe osteomalacia.

Answer 30

Defective mineralisation of osteoid
May be asymptomatic
Muscle weakness (proximal)
Bone pain
Fractures

Question 31

What are the statistics for Paget’s disease?

Answer 31

Estimated to occur in 1-3% of people over the age of 55 years

Question 32

What is Paget’s disease?

Answer 32

Characterised by increased bone turnover
Results in overgrowth, bowing, pain, fractures and deformity
May be focal or multifocal

Question 33

What investigations would you do if you suspected Paget’s disease?

Answer 33

Bloods – Serum Ca, PTH, ALK P
X Rays
Radionuclide bone scans
Bone biopsy if malignant change is suspected

Question 34

What are the treatments for Paget’s disease (mainly non-pharma)

Answer 34

Walkers, sticks, orthotics
Supportive therapy
Analgesia if required
Bisphosphonates
Surgery

Question 35

What is osteogenesis imperfecta?

Answer 35

Inherited condition characterised by defective production of type I collagen

Question 36

What does osteogenesis imperfecta affect?

Answer 36

Bone. teeth, sclera, joints, tendons. heart valves and skin