Table Of Contents
Osteoporosis
Osteoporosis is a skeletal disease characterised by low bone mineral density and microarchitectural defects. This leads to increased fragility and susceptibility to fracture. It is commonly asymptomatic until fractures happen. It is diagnosed objectively using a DEXA Scan with a T-score ≤ – 2.5. The T-score is a measurement of standard deviations relative to the average healthy adult in their 20s.
Osteoporosis is a common disease process. It primarily occurs in women > 50 years.
Definition of terms
| Term | Definition |
|---|---|
| Osteoporosis | Low bone mineral density and microarchitectural defects. T-score ≤ -2.5 |
| Osteopaenia | Low bone mineral density and microarchitectural defects. T-score -1.5 to -2.5 |
| Osteomalacia | Disorder of bone mineralization with intact bone matrix. This is unrelated to osteoporosis or osteopaenia |
Differentials of pathologic fractures
| Category | Differentials |
|---|---|
| Metabolic disease | Osteoporosis, osteopaenia, Paget disease of bone, renal osteodystrophy, osteomalacia, primary hyperparathyroidsim, hyperthyroidis |
| Malignancy | Multiple myeloma, bony metastases |
- Risk factors for osteoporosis
- Age > 50 years: bone density naturally decreases
- Low estrogen
- Postmenopausal
- Early menopause
- Nulliparity
- White race
- Thin build: weight bearing activities strengthen bone
- Sedentary lifestyle: weight bearing activities strengthen bone
- Alcohol or tobacco use
- Diseases
- Hypogonadism
- Hyperthyroidism
- Medications
- Antiepileptics e.g. phenytoin
- Corticosteroids
- Deficiency
- Calcium
- Vitamin D
- Patient history
- Family history of osteoporosis or fracture
- Alcohol use
- Smoker
- Use of antiepileptic drugs or steroids
- Signs and symptoms
- Most fractures are subclinical or asymptomatic
- Wrist pain (distal radius fracture – most common)
- Vertebral pain (vertebral fracutre)
- Hip pain (may radiate to the knee, groin, or buttocks)
- Physical examination
- Thoracic hyperkyphosis
- Dowager’s hump (humpback)
- Decrease in height
- Point tenderness
- Gait instability
- Investigations
- DEXA scan: screening for all women over the age of 65 years. Women aged 60 – 64 may be screened based on clinical suscpiscion
- T-score -1.5 to -2.5 is osteopaenia
- T-score ≤ -2.5 is osteoporosis
- X-ray: for fracture (sudden, localized bony tenderness)
- Complete blood count: rule out multiple myeloma
- Normal in osteoporosis
- Pancytopaenia in multiple myeloma
- Serum calcium: rule out hypocalcaemia
- Normal in primary osteoporosis
- Hypocalcemia may cause secondary osteoporosis
- UEC: rule out renal osteodystrophy
- Abnormal in renal osteodystrophy (FOLLOW UP WITH ptf, mG AND 25-vIT d)
- Alkaline phosphatase: to rule out paget disease of bone
- Thyroid panel: rule out hyperthyroidism
- Low TSH and elevated T4 indicate hyperthyroidism
- UPEP and SPEP: rule out multiple myeloma in patients with multiple vertebral fractures
- DEXA scan: screening for all women over the age of 65 years. Women aged 60 – 64 may be screened based on clinical suscpiscion
- Treatment
- Bisphosophonates e.g. alendronate, risedronate, ibandronate, zoledronic acid**:** first-line
- Denosumab: first-line
- SERMs e.g. raloxifene: second-line for women
- PTH analgos e.g. teriparatide: second-line for both men and women
- Calcitonin: third-line
