Flashcards in Osteoporosis Deck (47):
What is the function of osteoprogenitor cells?
To give rise to osteoblasts (they are the stem cell population)
What is the function of osteoblasts?
Responsible for bone formation
Where are osteoblasts located/positioned?
They cover the surface of bone
What is the function of osteocytes?
Maintain the bone matrix through cell-cell communication and influence bone remodelling; they are also mechanosensing
Where are osteocytes found?
Embedded in lacunae
What is the function of osteoclasts?
Resorb bone matrix by demineralisation
What are osteoclasts derived from?
Between what ages is bone gained?
1 must be greater than 2 in order for bone gain to occur. What do 1 & 2 stand for?
Between what ages is bone mass fairly stable?
Beyond what age is bone lost?
What are the figures for people affected by osteoporosis for men & women respectively?
1 in 12 men
1 in 3 women
List 3 structural differences in osteoporotic bone when compared to normal bone.
Decreased size of osteons (Haversian system)
Thinning of trabeculae
Enlargement of Haversian and marrow spaces
List some risk factors associated with osteoporosis (5).
Previous fragility fracture
Name two non-environmental factors that affect bone mass substantially.
List some lifestyle and nutritional risk factors of osteoporosis.
List 5 medical conditions that could potentially predispose to osteoporosis.
Early menopause (i.e.1 year)
Chronic renal, pulmonary or GI disease
List some drugs that could increase the risk of osteoporosis.
Chronic corticosteroid therapy (increase risk of fracture by 2-3x)
Excessive thyroid therapy
Gonadotrophin releasing hormone agonist or antagonist
What fracture type and by how much does a previous wrist fracture increase the risk of?
Future hip fracture: x2
Future vertebral fracture: x3
List the 6 non-modifiable risk factors for osteoporosis
Long term steroid therapy
List the 7 modifiable risk factors for osteoporosis.
Vitamin D deficiency
What is the name given to Type 1 osteoporosis?
What type of bone does Type 1 osteoporosis mainly affect?
What type of bone fracture is common in Type 1 osteoporosis?
Distal radius fracture
What hormone loss is Type 1 osteoporosis related to?
What is the ratio of females to males that suffer from type 1 osteoporosis?
What type of bone does Type 2 osteoporosis mainly affect?
Both cancellous & cortical bone
What type of bone fracture is common in Type 2 osteoporosis?
What compound/mineral lack is Type 2 osteoporosis related to?
Calcium - related to poor calcium absorption
What is the ratio of females to males that suffer from type 2 osteoporosis?
What is the 'title' given to Type 2 osteoporosis?
Age related in those over 75 years
What brings about disuse osteoporosis?
Not enough pressure or force is put on the bones
What is the result of disuse osteoporosis?
Low energy trauma frequent
Increase in bone fragility
Name the 4 most common sites for osteoporotic bone fracture
Neck of femur
Give the stats on hip fractures, i.e. what percentage are fatal, recover fully, are permanently disabled.
Full Recovery: 30%
Permanent disability: 50%
What type of investigations are carried out in diagnosis of osteoporosis?
FBC (full blood count)
Thyroid function tests
Testerostone & gonadotrophin levels (in men)
X-ray of lumbar & thoracic spine
Bone mineral density
What is used to measure bone mineral density?
DEXA (dual-energy x-ray absorptiometry scan)
Two distinct energy peaks - one absorbed by soft tissue, the other by bone
How would you calculate Bone Mineral Density?
Subtract one peak from the other (from DEXA)
With regard to DEXA scores, what is the T score?
A comparison with a young adult of the same gender with peak bone mass
A T score of greater than -1 is ... ?
Between what T scores is a bone classes to be osteopenic (bone thinning)?
-1 ---> -2.5
A T score of less than -2.5 is typical of ... ?
What is the Z score?
A comparison of the patient's bone mineral density with data from the same age/sex/size
List the 5 forms of treatment for osteoporosis.
Hormone replacement therapy
Name 2 anabolic agents.
Name 2 bisphosphonates.