Week 2. Osteoporosis Flashcards
(8 cards)
Define the term osteoporosis
A bone mineral density which is >2.5 standard deviations below peak bone mass (20-year-old sex-matched healthy person average) as measured by DEXA scan
Briefly outline the classification of Osteoporosis
Generalised (diffuse)
- Genetic (congenital) – eg Turner (XO) or Klinefelter (XXY) syndrome, anaemias (sickle cell, thalassemia, haemophilia)
- Deficiency states – Malnutrition, scurvy, protein deficiency, alcoholism and liver disease
- Neoplastic – Myeloma, leukaemia, lymphoma, metastatic disease
- Iatrogenic – Heparin, Dilantin, steroid-induced
- Miscellaneous – Involutional, post-menopausal, amyloidosis paraplegia, weightlessness, idiopathic
Localised (regional)
- Secondary to specific, identifiable aetiologies
- Less common than generalized
- Causes:
- Immobilisation/disuse
- Pain
- Infection
- Paget’s disease (hot phase)
- Transient regional OP
- Regional migratory OP
- Idiopathic juvenile OP
Generalised OP can be further classified as: Primary - Type I (post-menopausal) - Type II (involutional) - Idiopathic
Secondary
- Endocrine
- Drug-induced
- Miscellaneous
Compare Type I and Type II osteoporosis
Type I (post-menopause)
- Females 48-55
- Aetiology, changes in oestrogen levels
- Typically affects trabecular bone
- Common fractures, vertebral crush fractures and Colles’
Type II (involutional)
- 2:1 female/ male, >70yoa
- Aetiology, Chronic, mild -ve calcium balance. Increased sensitivity to PTH. Decrease stimulation of osteoblasts (sedentary lifestyle)
- Trabecular and cortical bone typical fracture sites
Which endocrine conditions are known to play a role in the development of osteoporosis.
- Glucocorticoid excess - excessive glucocorticoids decreases osteoblastic activity and increases osteoclastic activity, as well as decreasing GI Ca2+ absorption and increasing urinary excretion. This leads to decreased bone formation and increased bone resorption.
- Hyperparathyroidism - PTH inhibits increase bone remodeling and resorption bia stimulation of osteoclastic activity
- Diabetes
What are the main symptoms of uncomplicated osteoporosis? Discuss
Uncomplicated
- Usually asymptomatic - often delayed diagnosis. Look for in history and physical observation (endomorph, sedentary etc)
- May have aching pain (especially back pain)
What is the main complication of osteoporosis? Discuss.
Complications (fracture)
- Typically vertebral crush fractures (minimal/ no trauma typically T8 or bellow)
These ssx include: acute pain which subsides within days, +/- local tenderness, aggrevated weight bearing, multiple crush fractures: kyphosis full aching pain
- non-vertebral fractures - usually secondary to falls.
Can labratory investigations be used to diagnose osteoporosis discuss
3 methods:
- Radiographic and US measurement of bone desnity. Osteopenia (-1 to -2.5 deviations form peak bone density ) Osteoporosis (>2.5 deviations from peak bone density)
- Labratory biochemical markers - may show markers that indicate secondary OP
- Bone biopsy with pathological assessment
Discuss the radiological manifestations of osteoporosis
- Reduced radiodensity (more radiolucent) - due to decreased bone density
- Cortical endplate prominence - most stress on endplates, therefore increased density relative to rest of VB
- Loss hos horizontal trabeculae
- Wedge / crush fractures - may be evident due to stress on weakened vertebrae
- cortical thinning
