IC 18: Approach to the Management of Osteoporosis

Question 1

What is osteoporosis characterised by?

Answer 1

• Low bone density
• Microarchitecture disruption (impaired mineralisation)
• Decreased bone strength
• Increased risk of fracture

Question 2

How is bone resorption and formation in osteoporosis?

Answer 2

Bone resorption > bone formation

Question 3

What causes the decrease in bone mass for osteoporosis?

Answer 3

• Age
• Menopause
• Low serum calcium
• Alcohol consumption
• Smoking
• Physical inactivity
• Medication use (glucocorticoid use, PPI)
• Secondary to other diseases

Question 4

What is the clinical manifestations of osteoporosis?

Answer 4

• Asymptomatic
• Often undiagnosed until presented with fragility fracture (low-trauma) (usually don’t cause fracture in normal humans) (spine, hip, wrists)

Question 5

What patients should be assessed for osteoporosis and associated risk?

Answer 5

• Post-menopausal women
• Men >= 65 year old
• Especially if risk factors present

Question 6

What are the risk factors for osteoporosis and consequent fracture?

Answer 6

• Family history of osteoporosis or fragility fractures
• Previous fragility fracture
• Ageing
• Low body weight
• Height loss (>2cm within 3 years)
• Early menopause (45 years and younger)
• Certain meds (like prolonged corticosteroid use)
• Low calcium intake (<500 mg/day)
• Excessive alcohol intake
• Smoking
• Prolonged immobility
• History of falls
• Presence of diseases that can lower bone density or increase fracture risk like DM or any inflammatory rheumatic disease

Question 7

What does the osteoporosis self-assessment tool for Asians (OSTA) reveal?

Answer 7

• High risk (>20) to consider DXA scan as the chance of finding osteoporosis is high
• Medium risk (0-20) to consider DXA scan if any other risk factor for osteoporosis is present
• Low risk (<0) to consider deferring DXA

Question 8

How is a diagnosis for osteoporosis made?

Answer 8

• History of fragility fracture at vertebral, hip, wrist, humerus, rib or pelvis (occurs spontaneously or from minor trauma) OR
• Bone mineral density measurement using DXA hip and/or spine reveals that patient is likely osteoporotic

Question 9

What does the bone mineral density (BMD) measurement using DXA hip and/or spine reveal?

Answer 9

• T-score < -2.5 SD means osteoporosis
• T-score -1 to -2.5 SD means osteopenia
• T-score >= -1 SD means normal bone density

Question 10

What is the difference between T-score and Z-score of BMD measurement using DXA hip and/or spine?

Answer 10

• T-score compares BMD against a young adult
• Z-score compares BMD against expected BMD for the patient’s age and sex (Z-score >= -2 SD suggests coexisting problems that can contribute to osteoporosis)

Question 11

What tests should be performed to exclude secondary causes of bone loss?

Answer 11

• Creatinine
• Full blood count
• Corrected calcium
• 25-hydroxy vitamin D
• Thyroid-stimulating hormone
• Erythrocyte sedimentation rate
• Alkaline phosphatase
• Serum phosphatase
• Spot urine calcium/creatinine ratio
• Serum total testosterone

Question 12

What tool can be used to evaluate fracture risk?

Answer 12

Fracture risk assessment tool (FRAX)

Question 13

When should anti-osteoporosis treatment be initiated?

Answer 13

• Major osteoporotic risk >= 20%
• Hip fracture risk > 3%

Question 14

When is FRAX score usually used?

Hint: remember algorithm

Answer 14

• If T-score from DXA scan is between -1 to -2.5
• FRAX score can be used to estimate the fracture risk and to determine if treatment should be given or not

Question 15

When are patients treated for osteoporosis?

Answer 15

1. Patient presenting with fragility fracture
2. Patient without fragility fracture but DXA BMD T-score of <= -2.5
3. Osteopenic (DXA BMD T-score between -1 and -2.5) without a fragility fracture but with high fracture risk of FRAX score

Question 16

What are the contraindications for oral bisphosphonate therapy?

Answer 16

• CrCl <30
• Hypocalcemia
• Oesophageal or gastric abnormalities
• Inability to stand/sit upright for >= 30 mins
• Aspiration risk

Question 17

What are the contraindications for IV bisphosphonate (zoledronic acid)?

Answer 17

• CrCl <35
• Hypocalcemia

Question 18

What are the side effects of bisphosphonate therapy?

Answer 18

• Osteonecrosis of jaw
• Atypical femoral

Question 19

What is the treatment duration for bisphosphonates?

Answer 19

Oral: 5 years
IV: 3 years

Question 20

Which osteoporosis medication has concerns in renal impairment patients?

Answer 20

• IV bisphosphonate not for CrCl <35
• Oral bisphosphonate, teriparatide and raloxifene not for CrCl < 30

Question 21

What are the risk factors for osteonecrosis of the jaw on bisphosphonate therapy?

Answer 21

• Tooth extraction or other invasive dental procedure
• History of cancer, radiotherapy
• Poor oral hygiene
• Concommitant angiogenesis inhibitors, bisphosphonates, chemo, corticosteroids, denosumab
• Comorbids like anemia, coagulopathy, infection, preexisting dental or periodontal disease

Question 22

What advice should be given for patients to prevent osteonecrosis of the jaw?

Answer 22

• Smoking cessation
• Avoid invasive dental procedures during bisphosphonate therapy
• Maintain good oral hygiene

Question 23

How should management be done if patient has osteonecrosis of the jaw and atypical femoral fractures?

Answer 23

ONJ: discuss with dentist and consider discontinuing therapy
Atypical femoral fracture: discontinue

Question 24

What should be checked prior to initiating therapy for osteoporosis?

Answer 24

• Serum calcium
• Vitamin D levels (>= 20-30 but < 50-100)

Question 25

What lab parameters should be measured for a patient on bisphosphonate therapy?

Answer 25

• Serum creatinine
• Serum calcium
• Serum vitamin D level

Question 26

What are the non pharm advice for patients with osteoporosis?

Answer 26

• Appropriate calcium intake (1000mg/day for 51 and old, 800mg/day for 19 to 50)
• Optimise vitamin D intake (51 to 70 years old 600 iu/day, >70 800IU/day)
• Advise on appropriate weight-bearing, muscle-strengthening and balance exercise
• Limit caffeine intake (<=2 cups)
• Advise on smoking cessation and appropriate alcohol intake (<= 2 cans or 2 cups)
• Educate on fall risk, home safety and footwear
• Educate about osteoporosis and fragility fractures and implications

Question 27

What are the DDIs associated with taking serum calcium or serum vit D?

Answer 27

• Calcium: PPI, fibre, iron, tetracyclines, fluoroquinolones, bisphosphonates, thyroid supplementation
• Vit D: rifampin, anticonvulsants, cholestyramine, orlistat, aluminium-containing products