Osteoporosis

Question 1

What is Osteoporosis?

Answer 1

A fall in bone mineral density, increasing risk of fractures (particularity pathological fractures). These fractures commonly occur in the spine, forearm, hip and shoulder. Osteoporosis is caused by an increased activity of osteoclasts to osteoblasts, leading to increased breakdown of bone tissue.

Question 2

What are the causes of Osteoporosis?

Answer 2

A - Crohns (Malabsorption of Ca2+)
M - Menopause (oestrogen suppresses osteoclasts), Hyperparathyroidism (increased bone resorption rate), Malabsorption
D - Long term steroid use (Reduce osteoblast activity), Alcohol/Smoking

Question 3

What will you find in a history taking of Osteoporosis?

Answer 3

Symptoms:
Low impact/unnecessary fracture
Increased fracture rate

Risk Factors: SHATTERED
Smoking
Hyperthyroidism/Hyperparathyroidism/Hypercalciuria
Alcohol
Thin 
Testosterone low
Early Menopause
Renal or liver failure
Erosive/Inflammatory conditions e.g. RA or Multiple Myeloma
Dietary Ca2+ low/Malabsorption 

Specific Questions to ask:
Work out risk of falling - Frailty score
Work out Frax tool
Getting Shorter - Kyphosis
Diet/Underlying GI conditions that may cause malabsorption 

Differentials:
Multiple myeloma - Weight loss
Osteomalacia - Presents in the same way, differentiated with bone biopsy showing poor mineralisation.
CKD causing bone disease (VIt D metabolism affected) - history of renal failure
Primary hyperparathyroidism - signs of hypercalcaemia, including anorexia, nausea, constipation, and abdominal pain.

Question 4

What will you find on examination of a patient with of Osteoporosis?

Answer 4

End of the bed:
Low BMI

Chest:
Kyphosis from asymptatic spinal fracture

Question 5

What investigations will you order in suspected osteoporosis?

Answer 5

FRAX tool to decide if you do a dexa scan
Fracture risk assessment
Age, Sex, Weight, Height, Previous hip fracture, Smoking, Glucocorticoids, RA, Alcohol

Bloods: - Should all be normal if truly primary osteoporosis
LFT’s - To look at ALP, which will be raised in osteomalacia
Ca2+ - Hypocalcaemia could indicate osteomalacia, Hypercalcaemia could indicate hyperparathyroidism
Serum Albumin - Indicates nutritional state
UnE - Look at renal function for CKD
serum 25-hydroxy vitamin D - Rule out vitamin D deficiency
Phosphate - Low serum phosphate levels could indicate osteomalacia.
PTH - Rule out hyperparathyroidism
Serum Testosterone in males - reduced levels cause reduced oestrogen (hypogonadism)

Imaging:
Xray of any presenting fractures 
DEXA scan – Assesses Bone Density
T score - Gives result compared to young healthy population. Used to asses if there is osteoporosis
-1 to 2.5 = Osteopenia

Question 6

What is the treatment of Osteoporosis?

Answer 6

Lifestyle
Improve exercise, especially weight bearing exercise and balance exercises to reduce risk of fall
Reduces weight - Stimulates osteoblasts
Calcium and vitamin D supplementation if deficient, otherwise increases dietary intake
Stop Smoking and drinking
Fall prevention programme based at home with OT

Medical - Start medical treatment when you think risk of fracture outweighs side effects. E.g. Patients at risk of fall have lower threshold. Also start in all patients on long term steroids
Treat any underlying cause
1st Line - Weekly Alendronic Acid (Bisphosphonate) – review needed every 5 years. Destroys osteoclasts
2nd Line - SERMS e.g. Raloxifene (Selective estrogen receptor modulator - oestrogen agonsist)can be taken twice a year