Introduction
Osteoporosis is a condition where bones gradually decrease in bone mineral density, thus increasing the likelihood of fragility fractures. Fragility fractures are fractures that occur as a result of mechanical forces which would not usually lead to a fracture. According to NICE, one of the most common sites of osteoporotic fractures is the spine (vertebra). These types of fractures often present with acute onset back pain, however, patients can also be asymptomatic. Osteoporosis is commonly associated with advancing age and is a major cause of disability and reduced life expectancy in older populations.
Epidemiology
- Incidence: 50.00 cases per 100,000 person-years
- Peak incidence: 70+ years
- Sex ratio: more common in females 2:1
| Condition | Relative incidence |
|---|---|
| Lower back pain (non-specific, without sciatica) | 60.00 |
| Bone metastases | 2.00 |
| Osteoporotic vertebral fracture | 1 |
| Neoplastic spinal cord compression | 0.20 |
| <1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Aetiology
Risk factors for osteoporotic fractures
- Advancing age is a major risk factor osteoporotic fractures: Women ≥ 65 years old and men ≥ 75 years old should be considered for fracture risk assessment. Women in this age bracket are almost certainly post-menopausal, therefore have reduced oestrogen levels - this is a risk factor for osteoporosis.
- Previous history of a fragility fracture
- Frequent or prolonged use of glucocorticoids
- History of falls
- Family history of hip fracture
- Alternative causes of secondary osteoporosis e.g. Cushing’s disease, hyperthyroidism, chronic renal disease
- Low BMI (< 18.5)
- Tobacco smoking
- High alcohol intake: > 14 units/week for women, > 21 units/week for men
Clinical features
Patients with osteoporotic vertebral fractures typically present with:
Signs:
- Asymptomatic: an osteoporotic vertebral fracture may be diagnosed through an incidental finding on X-ray
- Acute back pain
- Breathing difficulties: changes in the shape and length of vertebrae lead to the compression of organs such as the lungs, heart and intestine
- Gastrointestinal problems: due to compression of abdominal organs
- Only a minority of patients will have a history of fall/trauma
Signs:
- Loss of height: vertebral osteoporotic fractures of lead to compression of the spinal vertebrae hence a reduction in overall length of the spine and thus the patient becomes shorter
- Kyphosis (curvature of the spine)
- Localised tenderness on palpation of spinous processes at the fracture site
Investigations
Investigations:
Other investigations:
In order to assess the likelihood of future fractures, risk factors are taken into account and a dual-energy X-ray absorptiometry (DEXA) scan should be considered. DEXA scans essentially assess bone mineral density. According to NICE, the FRAX tool or QFracture tool can be used to estimate the 10-year risk of a fracture. These tools each require the clinician to input patient information into a form and this information is used by the programme to calculate the risk.
- X-ray of the spine: This should be the first investigation ordered and may show wedging of the vertebra due to compression of the bone. An X-ray of the spine may also show old fractures (which can have a sclerotic appearance)
Other investigations:
- CT spine: gives a more detailed view of the bone structure, therefore can visualise the extent/features of the fracture more clearly
- MRI spine: Useful for differentiating osteoporotic fractures from those caused by another pathology e.g. a tumour
In order to assess the likelihood of future fractures, risk factors are taken into account and a dual-energy X-ray absorptiometry (DEXA) scan should be considered. DEXA scans essentially assess bone mineral density. According to NICE, the FRAX tool or QFracture tool can be used to estimate the 10-year risk of a fracture. These tools each require the clinician to input patient information into a form and this information is used by the programme to calculate the risk.