Osteoporosis Flashcards
Define osteoporosis
Skeletal disease characterised by reduced bone density and micro-architectural defects in bone tissue, resulting in increased bone fragility and susceptibility to fracture
Defined as T-score <-2.5
Aetiology of osteoporosis
Low early peak bone mass or loss of bone mass with ageing (<50 years)
Post menopausal
Secondary:
Malignancy : myeloma, metastatic carcinoma
Endocrine: Cushing’s disease, thyrotoxicosis, primary hyperparathyroidism, hypogonadism
Drugs: corticosteroids, heparin
Rheumatological: rheumatoid arthritis, ankylosing spondylitis
GI: Malabsorptive syndrome e.g. Crohn’s, UC, coeliac, gastrectomy, liver disease (primary biliary cirrhosis), anorexia
Risk factors for osteoporosis
Female, post-menopause
Older age (>50 women, >65 males)
Low BMI
FHx
Smoking, alcohol use
Prolonged immobilisation
Vitamin D deficiency/low calcium intake
Corticosteroid use, PPIs, heparin, anti-epileptics, hormone blockers
T1DM, RhA, CLD/CKD, malabsorption, anorexia
Symptoms of osteoporosis
Often asymptomatic until fractures occur
Femoral neck fractures (commonly after minimal trauma)
Vertebral fractures
Back pain
Impaired vision
Weakness
Balance issues
Colles’ fracture of the distal radius after a fall onto outstretched hand
Signs of osteoporosis on examination
Kyphosis
Impaired gait, imbalance and lower-extremity weakness
Vertebral tenderness, esp. on percussion
Severe pain with leg shortened and externally rotate (Neck of femur fracture)
Investigations for osteoporosis
FRAX scoring: calculates 10 year fracture probability
Urinary free cortisol
Urine protein electrophoresis
Bone profile: NORMAL
Renal screen
TFTs
B12 and folate
CRP/ESR
Testosterone
Oestrogen
Serum protein electrophoresis
DEXA: T score <-2.5
QUS heel: if no access to DEXA
X-ray wrist, heel, spine, hip: ?fractures
Quantitative CT: reduced trabecular bone density (If not access to DEXA)
Management for osteoporosis
Conservative:
- Weight-bearing exercise
- Stop smoking, reduced EtOH
- Vit D/Ca supplements
- Falls prevention and risk assessment
- Education, royal osteoporosis society
Medical:
1. Bisphophonates e.g. alendronate,
2. Risendronate, etidronate, zoledronic acid
3. Strontium ranelate AND Selective oestrogen receptor modulators (SERMs) e.g. raloxifene, tamoxifen)
Other
- Teriparatide 18 months (PTH analogue) - daily SC injection
- Oestrogens (HRT) - not recommended unless symptomatic menopause
- RANK-L inhibitors (Denosumab) - 6 monthly SC injection
- NEW: sclerosin analogue
What are the MOAs and SEs for bisphosphonates and SERMsCo
bisphosphonates e.g. alendronate
Decreases bone resorption as it is much stronger and osteoclasts cannot turnover as quickly
BUT is highly irritative to the stomach
BUT they also bind calcium at the same time - so if taken with milk it would not be absorbed and be inactivated
Taken once a week upright with plenty of water and nothing else, do not eat for 30 minutes after
IV zolendronate is becoming popular as it is only given once a year
May have. a drug holiday after 5 years
SERMs
Tamoxifen - oestrogen antagonist for the breast (so does not increase breast Ca risk) and SERM for bone
BUT Worsens the symptoms of menopause
Complications of treatment for osteoporosis
Alendronate: Osteonecrosis of jaw, fli-like symptoms, atypical femur fractures, oesophagitis
Raloxifene: worsens menopausal symptoms, increased VTE risk
Strontium ranelate: increased CVD, VTE, SJS
Complications of osteoporosis
Hip fractures, fatal in 20%
Vertebral fractures → kyphosis → breathing difficulties, GI problems, difficulties in bending, reaching and ADLs
Forearm fractures → pain and disability
Prognosis for osteoporosis
With preventative treatment, fragility fractures of the hip, vertebrae, and wrist can be avoided.
Prognosis is good for people at risk of osteoporosis if steps are taken to prevent decline in bone density and strength
