Bone Diseases Flashcards
What is arthritis?
inflammation of joints
What is arthrosis?
non-inflammatory joint disease
What is arthralgia?
joint pain
Bone is a mineralised connective tissue with 3 main features. What are they?
- load bearing
- dynamic
- self-repairing
What does it mean by saying bone is dynamic?
- It is continuously changing – always being formed, resorbed and adapting due to changing stresses in the environment
The cycle of remodelling of bone takes place over a 3-6 month period and requires the correct amount of what? (3)
- calcium
- Vit D
- phosohate
Bone is a store for what?
Calcium
What are the 2 types of calcium you can find in the bone?
Exchangeable and non-exchangeable
What happens to the exchangeable calcium found in the bone?
It can move into the ECF if more calcium is required there
Why does exchangeable calcium move into the ECF?
because the ca level in the ECF needs to be maintained at a prcise level as it is responsible for things such as nerve and muscle function
Apart from via bone, how is calcium absorped into the ECF and how is it lost?
absorption = through gut
loss = gut and urine
Calcium levels in the ECF are rugulated by what?
Describe the process.
The parathyroid hormone
If the serum calcium level falls, there is an increase in production of parathyroid hormone (from parathyroid glands) which increases calcium release from bone and redices renal calcium excretion.
Hypoparathyroidism leads to what?
Low serum calcium
Hyperparathyroidism can be primary or secondary. Describe both.
- Primary = gland dysfunction (tumour)
- High serum calcium results
- Inappropritate action of osteoclasts
- Secondary = caused by low serum calcium
- Oestoclasts activated appropriately to increase calcium levels
- Both result in increased bone reabsorption – will show up as radiolucencies in radiogrpahs
How is Vit D absorped into the body?
Via skin from sunlight or from diet
What can cause problems with Vit D absorption?
- Low sunlight exposure
- Housebound
- Dark skinned in a Northern Country (pigmentation = less absorption of sunlight)
- Poor GI absorption
- Poor nutrition
- Small intestine disease – malabsorption
- Drug interactions
- Some antiepilepic drugs (Carbamazepine, phenytoin)
- Vit D deficiency is normally a combination of factors
What is osteomalacia?
- osteoid matrix is formed properly and in the correct amount but is poorly mineralised
- leads to a soft tissue
Osteomalacia is called what during bone formation?
Rickets
Both osteomalacia and rickets are related to what?
A calcium deficiency - the serum calcium levels are preserved at the expense of the bone
The effects of osteomalacia/rickets on the bone are what?
- Bones bend under pressure ‘bow legs’
- Vertebral compression in adults
- Bones ‘ache’ to touch
What are some effects of hypocalcaemia?
- Muscle weakness
- Trousseau and Chvostek signs positive
- Carpal muscle spasm
- Facial twitching from VII tapping
How is osteomalacia/rickets managed?
- Correction of the cause
- Malnutrition
- Control GI disease
- Sunlight exposure
- 30mins x 5 weekly
- Dietary Vit D
What is osteoporosis?
- reduced quantitiy of normal mineralised bone
- the osteoid matrix is lay down properly and mineralised properly, there is just less of it
- is an age-related change and is inevitable.
What are risk factors for osteoporosis?
- Age
- Female sex
- Endocrine problems
- Oestrogen and testosterone deficiency
- Cushings syndrome
- Genetic
- Family hx
- Race – caucasian and asian women
- Early menopause
- Patient factors
- Inactivity
- Smoking
- Excess alcohol use
- Poor dietary calcium
- Medical drugs use
- Steroids
- Antiepileptics
- These drugs affect calcium metabolism
At what age is peak bone mass?
24-35 years old
Whats the difference beween peak bone mass and the decline in males and females?
- Men tend to have a higher peak bone mass than females
- oestrogen withdrawl (menopause) increases the bone mass loss rate in women
What are the effects of osteoporosis?
- Increased risk of bone fractures
- Especially long bones like the femur
- The bone loss is no longer adequate to support stresses and sudden forces
- Effects on the vertebrae
- Height loss
- Kyphosis & Scoliosis
- Nerve root compression – back pain
What steps can be taken to help prevent osteoporosis?
- Build maximum Peak Bone Mass
- Exercise
- High dietary calcium intake
- Reduce rate of bone mass loss
- Continue exercise and calcium intake
- Reduce hormone related effects
- Oestrogen hormone replacement therapy
- Reduce drug related effects
- Consider ‘osteoporosis prevention’ drugs – biphosphonates
- Hormone replacement therapy after menopause
How do biphosphonates work?
Reduce osteoclast action
Why are biphosphonates relavent in dentistry?
concerned about medication related/induced osteonecrosis of the jaw (MONJ)
Poorer wound healing and bone repair
extractions
