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
What are contraindications for bisphosphonate treatment?
GORD + GI bleeding
Why is denoximab a better option for dementia patients?
SC injection every 6 months therefore better concordance in elderly
What is osteonecrosis of jaw a side effect of?
Denoximab
What can bisphosphonates cause over time?
Stress femur atypical fractures
Treatments other than bisphosphonates for osteoporosis?
Activated vit D
Denosumab injections
SERMS - selective oestrogen receptor modulator
Strontium ranelate
Risk factors for osteoporosis
- SERMS
- Andonate
- HT
- STEAR
What is a fragility fracture?
Fracture following a fall from standing or less, vertebral may be spontaneous or as a result of routine activities such as bending or lifting
What does presentation age of osteoporosis depend on?
Genetics
Levels of nutrtition - vit D and calcium
Sex hormone levels
Physical acitvity levels
When is peak bone density decline in women?
Accelerates after the menopause for 5 to 10 years
Starts to decline in the 5th decade for women adn men
What hormonal changes cause rate of bone loss to increase?
Oestrogen deficiency
Decreased testosterone
hyperparathyroidism
Risk factors affecting bone mineral density
Endocrine disease - DM. hyperthyroidism, hyperparathyroidism
GI conditions causing malabsorption - Crohns, UC, coeliac, chronic pancreatitis
CKD
Chronic liver disease
COPD
Menopause
Immobility
BMI <18.5kg/m2
Risk factors the decrease bone strength but not bone mineral denstiy?
Age
Oral corticosteroids
Smoking
Alcohol - 3+ units
Prev fragility fracture
Rheumatological conditions eg arthritis, inflam arthropathies
Parental history of hip fracture
Drugs that decrease bone strength over time
SSRIs
PPIs
Anticonvulsant drugs - carbamaxepine
Risk factors for falls
Impaired vision
Neuromucular weakness and incoordination
Cognitive impairment
Use of alcohol and sedative drugs
Risk of fracture who assess in
women over 65 years or 50-64 with risk factors
Men over 75 years - 50-74 with risk factors
Which risk factors mean you do an early fracture risk score for osteoporosis?
Prev osteoporotic fragility fracture
Current ise or requent corticosteroids
Historyh of falls
Low BMI
Smoker
Alcojol intake over 14 units a week
Secondary osteoporosis