Bone Disorders Flashcards
What is Osteoporosis?
Progressive systemic skeletal disease characterised by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture
What symptoms occur with osteoporosis?
None
Where are common fracture sites?
Neck of femur
Vertebral body
Distal radius
Humeral neck
What does continual remodelling cycle called bone remodelling units contribute to?
Calcium homeostasis and skeletal repair
What score systems are there for osteoporosis risk factors?
FRAX and Qfracture
Who should be assessed with score systems?
Anyone >50 with risk factors
Anyone
When should you refer to DXA?
Anyone with a 10 year risk assessment for any OP fracture of at least 10%
What can predict risk, without other risk factors being accounted for?
Bone mineral density
What is used for measuring bone mineral density?
DEXA scans
What is normal BMD?
within 1 of SD of young adult mean
What defines osteopenia?
BMD within >1 SD below young adult mean
What defines osteoporosis?
BMD >_2.5 SD below young adult mean
What defines severe osteoporosis?
BMD >_2.5 SD below young adult mean with fragility fracture
What score is reported if the patient is under 20?
Z score only
What bloods would be taken for osteoporosis?
U+E’s, LFT’s, Bone biochemistry, FBC, PV, TSH
What other things should be checked for in osteoporosis?
Protein electrophoresis Bence Jones proteins Coeliac antibodies Testosterone 250H vitamin D PTH
What can cause secondary osteoporosis?
Hyper(para)thyroidism Cushing's disease Coeliac, IBD, chronic liver, chronic pancreatitis CF, COPD CKD
What dieting can help with osteoporosis?
RNI 700mg calcium (2-3 milk portions)
Postmenopasusal - 1,000mg of calcium
Describe vit D and calcium supplementation
Calcium not to be taken within 2 hours of bisphosphonates
Used to reduce risk of non vertebral fractures
Explain bisphosphates
Antiresoptive agents - Alendronate and risedronate
Prevent bone loss at all sites
Reduce spine/hip fracture risk
How do bisphosphates work?
Analogues of pyrophosphate that absorb onto bone within matrix
Ingested by osteoclasts leading to cell death thereby inhibiting bone resorption
Filling of resorption sites by new bone increases BMD by 5-8%
Describe Zoledronic acid
Once yearly IV infusion for 3 years
5mg in 100mls of NaCl over 15 mins
describe Denosumab
Fully human monoclonal antibody that targets and binds with high affinity and specificity to RANKL (factor-kB ligand)
Prevents activation of RANK
Describe Strontium Renalate
Antiresorptive agent
3rd line agent
Contraindicated with thromboembolic disease, IHD, Peripheral artery disease, uncontrolled hypertension
