Osteoporosis Flashcards
What is osteoporosis defined by?
Low bone mass
Microarchitectual deterioration of bone tissue
Increase in bone fragility + fracture susceptibility
T score for osteoporosis
<2.5
Common sites fragility fractire
Vertebral bodies
Hip - NOF
Distal fractures
Proximal humerus
Pelvis
Which bone cells are multinucleated?
Osteocalsts
What is the function of osteoblasts?
Secrete osteoid - make bone
What is the function of osteoclasts?
Destroy bone - remodelling
Modelling vs remodelling of bone
Modelling - bone resorption and formation on seperate surafces - growth from birth to adulthood
Remodelling - maintains bone mass and structural integrity, resorption and formation at same site
Mineral depositions in bone
Calcium pyrophosphate
Phosphate
Features of long bones
tubular, cortical layer surrounding spongy trabecular bone
Felxible enogh to absorb stress but strong
What kind of bones are the vertebrae?
Long bones
Pathophysiology osteoporosisn
age → daily remodelling → resorption minerals on insede corticcal layer + in bone cavity → loss trabecular bone and widening of cavity
Fixed risk factors for osteoporosis
- Age
- Female - post menopausal
- Family hisotry
- Caucasian, asian more prone to osteoporosis
- Height loss
- Oestrogen deficiency
- Amenorrhea
- Early menopause
- Hysterectomy
Modifiable risk factors osteoporosis
- CKD → tertiary hyperparathyroidism
- Smoking
- Aclohol
- Low BMI
- Poor nutrition - low dietary calcium intkae
- Vit D deficinecy
- PTH abnormalities
- Eating disorders
- Insufficient exercise
- Frequent falls
- IBD
- Endocrine disorders
- RA
- T1/T2DM - insulin use, longer duration of disease independent of BMD
Medications that increase risk for osteoprorosis
- Corticosteroids
- THyroid hormone excess - medication or pathological
- Aromatase inhibitors - treatnent of breast cancer
- Androgen deprivation for prostate cancer treatment
- Thiazolidinediones
- Antidepressents, antiparkinsonia, antipsychotics, anxiolytics drugs, benzos, sedatices, H3 receptor agonists, PPIs
Scoring for osteoporosis
FRAX - infor about treatment threshold
What medicationand time frame is an indiciation for a DEXA scan?
Corticosteroids - 3 months
What is a DEXA scan? Where are they done?
Dual electron X ray absorptions
Done at lumbar spine, hip or femoral neck
Where does a T score come from?
DEXA scan
What does it mean if the T score is between -1 and -2.5?
Patient has low bone density (osteopenia) but not osteoporosis
Investigations for osteoporosis
Bone mineral density - DEXA scan
Bloods - FBC, bone profile, corrected calcium, magnesium, phosphate, CRP/ESR, RF + CCP, cancer markers
Multiple myeloma testing - immunoglobulins, protein electrophoresis
Urinary benstones proteins
What is considered mild, moderate and severe vertbral fracture based on height loss?
Mild - 20-25%
Moderate - 35 to 40%
Severe = over 40%
What guidelines do you use for osteoporosis?
NOGG
How minimise vit D and calcium low levels with bisphosphonated?
-Normal vit D + calcium levels before start
Give with adcalD3 - calcium and vit D
Why can you not lie down for 30 mins after taking alendronate?
Bisphosphonate - prevent oesophageal eroison