Bone Diseases Flashcards
What is arthritis?
Inflammation of joints
What is arthrosis?
Non-inflammatory joint disease
What is arthralgia?
Joint pain
What makes up bone?
Mineralised connective tissue
Calcium
Phosphate
Vitamin D
Describe the role of parathyroid hormone?
Maintains serum calcium level - raised if calcium levels fall
Increases calcium release from bone
Reduces renal calcium excretion
Describe serum calcium in hypoparathyroidism
Low serum calcium
Describe serum calcium in hyperparathyroidism
Primary - gland dysfunction results in high serum calcium
Secondary - caused by low serum calcium
Both result in increased bone resorption
Describe the action of vitamin D
Results in absorption of calcium
What are the problems with vitamin D?
Low sunlight exposure in Scotland
Poor GI absorption if nutrition is poor or in those with small intestinal disease
Drug interactions - carbamazepine and phenytoin
What is osteomalacia?
Poorly mineralised osteoid matrix
Poorly mineralised cartilage growth plate
What is osteoporosis?
Loss of mineral and matrix leads to reduced bone mass
What are the different types of osteomalacia?
If during bone formation - rickets
If after bone formation - osteomalacia
Both related to calcium deficiency
What investigations are done for osteomalacia?
Serum calcium - decreased
Serum phosphate - decreased
Alkaline phosphatase - very high
Plasma creatine - ??
Plasma parathyroid hormone - ??
What effects does osteomalacia have on bone?
Bones bend under pressure
Bones ache to touch
Vertebral compression in adults
What are the effects of hypocalcaemia?
Muscle weakness
Trousseau and Chvostek signs positive
Carpal muscle spasm
Facial twitching
How is osteomalacia managed?
Correct the cause:
Malnutrition - control GI disease
Sunlight exposure - 30 mins 5x weekly
Dietary vitamin C
Give some risk factors of osteoporosis
Female sex
Family history
Caucasian and Asian woman
Smoking
Excessive alcohol use
Who is affected by osteoporosis?
15% women age 50
30% women age 70
40% woman aged 80
Why are women affected more than men by osteoporosis?
Males have a higher peak bone mass
Oestrogen withdrawal increases bone mass loss rate in women
What are the effects of osteoporosis?
Increased bone fracture risk
Height loss from vertebrae compression
Lifetime risk of hip fracture
What are the average outcomes of osteoporosis related hip fracture?
20% increase in 5 year mortality
40% unable to walk unaided
60% unable to live independently
What can be done for osteoporosis prevention?
Build maximal peak bone mass - exercise and high dietary calcium intake
Reduce rate of bone mass loss
Consider osteoporosis prevention drugs - bisphosphonates
How is hormone replacement therapy used to treat osteoporosis?
Oestrogen only
Reduces osteoporosis risk but increases risk of breast cancer, endometrial cancer, and DVT
Give examples of bisphosphonates
Non-Nitrogenous - etidronate, clodronate
Nitrogenous - pamidronate, neridronate
How effective are bisphosphonates?
Reduce vertebral fracture risk by 50%
Reduce other fractures by 30-50%
