Orthopaedics Flashcards
What is the pathology of osteoporosis?
osteoporosis is a reduction in bone mineral density and disruption of the normal bone architecture causing increased bone fragility and fracture risk
there is an imbalance in remodelling of bone - osteoclast activity outweighs osteoblast
What are the risk factors for osteoporosis?
S - STEROIDS H - HYPERTHYROID, HYPERPARATHYROID A - ALCOHOL, smoking T - TESTOSTERONE decrease T - THIN (BMI <22) E - EARLY MENOPAUSE R - RENAL DISEASE, liver disease E - EROSIVE BOWEL DISEASE e.g. coeliac D - DIETARY INTAKE - decreased Ca, malabsorption
+ female, age, rheumatological conditions (RA), FH of hip fractures, previous fragility fracture
What does osteoporosis cause?
FRAGILITY FRACTURES - commonly vertebral, femoral neck or wrist
(otherwise asymptomatic)
What is a fragility fracture?
fracture after falling from standing height or less
Which score is used after a fragility fracture in osteoporosis? what does it assess?
FRAX SCORE - risk score for likelihood of another fracture in the next 10 years (before doing a DXA scan)
3 PERSON (age, sex, BMI) , 3 FRACTURE (previous fracture, FH of hip fracture, low bone mineral density), 3 INPUT (smoking, alcoholism glucocorticoids), 2 CONDITIONS (RA, secondary osteoporosis)
Which medications may worsen osteoporosis?
glucocorticoids (corticosteroids) e.g. prednisolone, budesonide anti epileptics PPI SSRI glitazones heparin therapy
After a fragility fracture or a FRAX score >10%, how is a patient assessed or diagnosed with osteoporosis?
DXA scan** (Dual x-ray absorptiometry) - measures bone mineral density
T score
How is osteoporosis managed conservatively?
reduce risk factors - smoking cessation, stop alcohol, BMI >22, diet rich in calcium
weight bearing exercises
fall prevention
treat secondary osteoporosis causes e.g. coeliac
What is the first line treatment for osteoporosis?
BISPHOSPHONATES e.g. oral alendronate (if experience SE try -> risedronate)
= inhibit osteoclast activity and bone resorption
+ ORAL CALCIUM AND VITAMIN D
What should you tell the patient when taking bisphosphonates?
- take first thing in the morning on empty stomach
- do not eat/ take other tabelts for 30 mins after taking
- do not lie down
- have a glass of water when taking tablet
What are the side effects of bisphosphonates?
oesophagitis *, atypical femoral fractures, gastric ulcers, osteonecrosis of jaw, hypocalcaemia
What are the other medical options for treating osteoporosis?
2nd line = STRONTIUM RANELATE
= increases deposition of new bone by osteoblasts and inhibits osteoclast
3rd line = OESTROGEN (HRT) OR SERMS e.g. raloxifene
= prevents bone loss and reduce risk of vertebral fractures
What is the pathology of pagets disease?
increased and uncontrolled bone turnover
- LYTIC PHASE -> increase bone resorption by osteoclasts
- SCLEROTIC PHASE -> rapid bone formation by osteoblasts but disorganised and mechanically WEAKER bone
How does pagets disease present?
usually in older people
bone pain - usually lumbrosacral, pelvis, femur
joint pain - secondary to bone deformity
What are the complications of pagets disease?
bowing of long weight bearing bones e.g. femur
deafness (compression of cranial nerve 8)
osteosarcoma
risks with surgery
How is pagets disease diagnosed?
- HIGH ALK PHOS ** - very high and also allows disease activity to be monitored
- x-rays - shows osteolysis and osteosclerosis
- isotope bone scans - identifies which bones affected
How is pagets disease managed?
- analgesics
- bisphosphonates + oral calcium + vit D
- joint replacements for severe joint destruction
What causes osteomalacia and what is it?
deficiency in vitamin D causes impaired mineralisation of the bone -> leads to softening of the bone (accumulation of unmineralised osteoid) -> bone becomes deformed and pseudo fractures
Who is at risk of osteomalacia?
- people who are housebound (lack of sun on skin)
- asian immigrants (lack of sun on dark skin)
- CKD (failure to activate vit D)
- liver disease e.g. cirrhosis (failure to activate vit D)
- malabsorption syndromes e.g. crohns, CF, coelaic, pancreatic disease (poor absorption of calcium and vitamin D)
- pregnancy
- alcohol, obesity
- drugs - corticosteroids, anti convulsants, rifampicin
How does osteomalacia present?
bone pain - tender, widespread
fractures
fatigue
proximal myopathy
How does rickets present?
when vit D deficiency in children affecting bone development
bone pain
impaired gait, delayed walking
bowing leg, knock knees
dental abnormalities
Which diseases does vitamin D deficiency cause?
rickets
osteomalacia
hypocalcemia
muscle weakness
How is osteomalacia diagnosed?
serum 25 (OH) D <25nmol/L
low serum calcium
high alk phos
high PTH
X-ray: translucent bands, pseudofractires
How is osteomalacia managed?
- calcium and vitamin D supplements
high doses for 6-12 weeks, IM for malabsorption syndromes, active calcitriol given to CKD patients - encourage sitting outside in the sun