Bone disease Flashcards
What is osteoporosis?
a condition of skeletal fragility characterised by reduced bone mass and micro architectural deterioration predisposing to an increased risk of fractures
bone density >2.5 standard deviations below the young adult mean
What are the secondary causes of osteoporosis?
drugs - steroid, sex hormone antagonist, lithium
endocrine - cushings, acromegaly, hypopituitarism
inflammatory - RA, AS, IBD
Nutritional - Vitamin D, calcium malabsorption
Genetic - marfan’s, turners
What are the main RFs for developing osteoporosis?
old age (particularly post-menopausal women) disuse perimenopausal state (HRT use minimises this) prolonged corticosteroid therapy (RA) endocrine disorders liver disease (alcoholic liver disease)
Describe the pathology of osteoporosis?
bone remodelling involves resorption by osteoclasts and replacement by osteoblasts. This is normally in equilibrium. Osteoporosis when this process is unbalanced resulting in the loss of bone mineral density
What is the clinical presentation of osteoporosis?
fracture is the only cause of symptoms - asymptomatic until fracture
How does a vertebral crush fracture present?
sudden onset of severe pain in the spine
localised at the affected level and radiating around to the front
only 1/3 vertebral fracture is symptomatic
increasing kyphosis, height loss and abdominal protuberance followed by a crushed vertebra
Which fractures are very suggestive of osteoporosis?
vertebrae
hip
wrist
What investigations should be used to investigate osteoporosis?
X-ray
DEXA bone scan
Biopsy can be used if diagnosis is in doubt
other tests: renal function bone profile (calcium, vitamin D, phosphate, alkaline phosphate, PTH) thyroid function test bone turnover markers multiple myeloma screen
What are the signs of osteoporosis on x-ray?
multiple fractures
looser zones
pencil thin cortices
increased alkaline phosphatase
What is the gold standard test for osteoporosis?
DEXA scan
What are lifestyle advice can be given to patients with osteoporosis?
improve calcium intake
weight bearing exercise
smoking cessation
What medical management is used in osteoporosis?
- vitamin D and calcium supplements
- bisphosphonates
- denosamab S/C ever 6/12 (monoclonal antibody)
Other: HRT, testosterone treatment, parathyroid hormone
What is the definition of osteomalacia?
normal deposition of bone osteoid by osteoblasts and normal bone architecture with inadequate mineralization of bone matrix
Which bisphosphonates are used to treat osteoporosis?
allerdronic acid - 70mg weekly
risedronate sodium
zolendronic acid IV
What prevention and lifestyle advice is given to women at risk of developing osteoporosis?
oestrogen hormone replacement therapy is the most effective way of maintaining bone density and reducing fracture risk.
don’t use is risk of breast cancer
continue for no longer than 5 years