Rheumatology (Diseases of Bone and Connective tissue disorders Flashcards
osteoporosis
reduced bone density leading to fragile bones more susceptible to fracutes
risk factors for osteoporosis
Primary
- age
- female (menopausal)
- low BMI
- corticosteroid therapy
- cushings syndrome
- alcohol
- smoking
Secondary
- hyperthryoidims
- primary hyperparathyroidism
- CKD
- Crohns, UC, coeliac
- RA
presentation of osteoporosis
asymptomatic usually prior to fragility fracture
common sites of fractures
- Vertebral compression fractures
- Neck of femur fractures
- Colles fracture
which tool is used to predict 10-year risk of fracture
FRAX tool
- if score high enough patient is sent for DEXA scan
Who should have their FRAX calculated
- Anyone on long-term oral corticosteroids or with a previous fragility fracture
- Anyone 50 and over with risk factors
- All women 65 and over
- All men 75 and over
who should have a DEXA scan
- Those with a high enough FRAX tool according to NOGG guidelines
- A DEXA may be arranged without calculating the risk in patients over 50 with a fragility fracture
- Treatment may be started without a DEXA in patients with a vertebral fracture
dual-energy x-ray absorptiometry (DEXA) scan
This measures BMD which is then given a T-score.
This is a score based on the BMD of a young reference population
- > -1.0 is normal
- -1.0 to -2.5 indicates osteopenia
- <-2.5 is classed as osteoporosis
further investigations to determine cause of osteoporosis
The next investigations are to identify or rule out any possible secondary causes:
- X-ray of the wrist, heel, spine, and hip
- CT if DEXA is not available
- Bone profile – calcium, phosphate, albumin, and ALP
- Serum PTH
- Serum 25-hydroxyvitamin D
- TFTs
- U&Es
- Serum testosterone (considered in all men with osteoporosis)
- Urine and serum protein electrophoresis
conservative management of osteoporosis/osteopenia
The first step is to address reversible risk factors.
- Increase physical activity
- Maintain a healthy weight
- Stop smoking
- Reduce alcohol consumption.
who requires pharmacological management of osteoporosis
- A FRAX 10-year probability of osteoporotic fracture >1%
- A hip or vertebral fracture
- T-score <-2.5
- T-score between -1.0 and -2.5 and a FRAX 10-year probability of osteoporotic fracture >3%
pharmacological management of osteoporosis
First line:
- Bisphosphonates e.g aldendronic acid 1-weekly
- and calcium and vitamin D (adCal)
Second line: if bisphosphonates not tolerated/ineffective
* Denosumab (monoclonal antibody that targets osteoclasts)
* and calcium and vitamin D (adCal)
Bisphosphonate options
1- Weekly
- Oral Alendronate (most popular)
- Oral Risedronate
1- Yearly
if alendronate not tolerated
- Zolendronic acid infusion
how much calcium and vitamin D
Calcium (at least 1000mg)
Vitamin D (400-800 IU)
Bisphosphonates have some important side effects:
- Reflux and oesophageal erosions
- Atypical fractures (e.g., atypical femoral fractures)
- Osteonecrosis of the jaw (regular dental checkups are recommended before and during treatment)
- Osteonecrosis of the external auditory canal
how should bisphosphonates be taken
taken on an empty stomach with a full glass of water. Afterwards, the patient should sit upright for 30 minutes before moving or eating to reduce the risk of reflux and oesophageal erosions.
osteomalacia
softening of the bones generally secondary to vitamin D deficiencies leading to incomplete mineralisation of bone
In children: rickets
RICKETS
rickets is characterised by defective mineralisation of the growth plate cartilage leading to skeletal deformities and reduction of growth secondary to vitamin D deficiency and subsequent incomplete bone mineralisation.
risk factors for osteomalacia
- Dark skin, especially in South Asian, African-Caribbean, and Middle-Eastern people
- Vitamin D deficiency is as high as 94% in otherwise healthy South Asian adults*
- Family history of vitamin D deficiency
- Age >65
- Pregnancy
- Obesity
- Covering of the face and body
- Housebound/institutionalised patients
- Poverty
- Vegetarianism
- Alcoholism
- Living in a high altitude