Osteoporosis Flashcards
osteocytes
sitting in lacunae, bone cells responsible for the maintenance of the bony matrix
lacunae
a cavity or depression (in bone)
osteoclasts
specialized cells that breakdown damaged bone tissue.
osteoblasts
specialized cell that help to form new bones and bone growth
fibroblasts
a cell that contributes to the formation of CT
Radical canaliculi
connect the Haversian canal to the lacunae
osteoporosis
A metabolic bone disorder characterised by a significant loss of bone mineral density (BMD) and a loss of microstructure
what is important to remember about osteoporosis?
There is a PROPORTIONAL loss of the organic and inorganic components of bone tissue. This means that the mineral to collagen ratio is within the reference range.
aetiology of osteoporosis
comes with age but is most prevalent in females, especially after going through menopause, due to the decrease in oestrogens and androgens, 1 in 2 women experience osteoporosis
idiopathic osteoporosis
occurs in children and young adults. Reasons are unknown
Oestrogen deficiency (type 1 osteo)
increase both bone resorption and formation, however osteoblasts are unable to keep up with osteoclasts. decreased estrogen leads to an increased secretion of inflammatory cytokines, increasing osteoclast recruitment and activity.
signs and symptoms of osteoporosis
- fractures, loss of height, stooped posture (kyphosis)
Kyphosis due to compression fracture of the vertebral bodies
- decreased respiratory function
- pinched nerves
- increased likelihood of fails
- immobilisation
- DVT and consequent embolisation
- Bed sores and infections
- Muscle atrophy
- death
DEXA scan
dual-energy x-ray absorptiometry scanning measures bone density in the hip, vertebrae and forearm
T-score
results of the DEXA which compares to young, healthy population
normal T-score
-1.0 or higher
osteopenia T-score (low bone density but not quite osteoporosis)
between -1.0 and -2.5
osteoporosis T-score
-2.5 or lower
prevention osteoporosis
- smoking cessation
- reduction of alcohol intake
- proper intake of calcium and vitamin D
- Low impact, weight-bearing exercises
How can a vitamin D deficiency increase the risk of osteoporosis?
Calcium can not properly be absorbed from the intestines, this increases release of parathyroid hormone (PTH), increasing the activity of osteoclasts
fracture
a medical condition where the continuity of the bone is broken, when a force applied exceeds the tensile or compressive strength of a bone
traumatic bone fracture
the bone is healthy but cannot withstand the force applied
pathological bone fracture
the bone is weakened by an underlying condition, and it snaps/breaks even when the trauma would not justify it.
incomplete fracture
the bone is damaged but still in one piece , hence its closed