History of minimal trauma fracture

The most easily-recognised risk factor for osteoporotic fracture is the presence of any vertebral or non-vertebral minimal trauma (fall from standing height or less) fracture. This also applies to vertebral fractures incidentally detected on radiographs. A trauma history may guide interpretation of vertebral deformities. Any minimal trauma fracture in someone aged >50 years prompt bone health assessment.⁵ DXA may be useful to determine whether the patient has reduced BMD (refer to Section 1.2).

Paternal or maternal history of hip fracture

A paternal or maternal history of hip fracture is the most reliable indicator of genetic risk of minimal trauma fracture. However, family history of other types of minimal trauma fracture should also be considered.

Height loss ≥3 cm and/or back pain suggestive of vertebral fracture

Some loss of height is typical with advancing age and is usually due to disc degeneration and/or scoliosis. The accurate measurement and recording of height are important; a height loss ≥3 cm, as measured by stadiometer, requires exclusion of vertebral deformity or fractures by X-ray. The greater the height loss, in the absence of obvious scoliosis, the greater the likelihood of vertebral fractures.

Sex

In each age group, men are at an approximately 50% lower fracture risk than women. However, once a man has experienced a fracture, his risk of a subsequent fracture is equivalent to that of a woman of comparable age who has also experienced a fracture.

Age

Fracture risk is strongly affected by age for both sexes. With each decade of life, the risk of minimal trauma fracture approximately doubles. Age as a fracture risk is independent of both BMD and clinical risk factors, such as risk of falling, which also increase with age and contribute to fracture risk. People aged <50 years are likely to be at low risk of fracture in the absence of other risk factors.

History of falls

A history of falls increases the risk of peripheral minimal trauma fractures for postmenopausal women and men of comparable age. This applies to falls without external cause that have occurred more than once in the past 12 months. Risk factors for falling include poor quadriceps strength, body sway, vitamin D deficiency, medications, visual impairment and environmental hazards (refer to Section 2.2).

Premature menopause or hypogonadism

Sex hormone deficiency leads to a reduction in bone mass and increased fracture risk. Early menopause (ie before age 45 years) and male hypogonadism (eg due to androgen deprivation therapy [ADT] to treat prostate cancer) are important causes of secondary osteoporosis. Male hypogonadism results in reductions in bone and muscle mass that improve with testosterone supplementation. Menopausal hormone therapy (MHT) in women with premature menopause mitigates the increase in bone resorption and preserves bone mass (refer to Section 3.4).

Low BMD

Relative fracture risk approximately doubles for each unit (SD) decrease in T-score, as measured by DXA. Postmenopausal women and men aged >50 years with osteoporosis (T-score ≤–2.5) are already at increased risk of minimal trauma fracture. Absolute fracture risk increases with both increasing age and decreasing BMD. The absolute risk for fracture is therefore high in postmenopausal women and men aged ≥70 years with a T-score ≤–2.5 (without fracture) and even higher in those with a T-score ≤–3.0. The strongest association between bone density and fracture risk exists when bone density at one site is used to predict the risk for fracture at that site – hence the focus on BMD at the hip, forearm, and spine⁵ (refer to Section 1.2).

However, any minimal trauma fracture in someone aged >50 years should be used as an opportunity to assess bone health. Because other factors (e.g., age, falls risk, poor vision) also affect fracture risk, the presence of a normal or only mildly low BMD may mean pharmacological therapy to increase BMD may not be required, and management in that person should focus on fall-prevention strategies.

Low body weight or weight loss

Low body weight (body mass index [BMI] <20 kg/m²) doubles the relative risk of a hip fracture in both women and men. An increased risk has also been demonstrated for spine and peripheral fractures. Unintentional weight loss is also associated with an increased risk of minimal trauma fracture. Anorexia nervosa is associated with an increased risk of developing osteoporosis.

Low muscle mass and strength

The gradual loss of skeletal mass and strength that occurs with advancing age is associated with an increased risk of falls and fragility fractures. Hip fracture patients with sarcopenia are 1.8-fold more likely to have osteoporosis than hip fracture patients with normal muscle mass.⁶ Insufficient protein intake and skeletal muscle inactivity are two important factors that cause skeletal muscle depletion (refer to Section 1.2).

Low physical activity or prolonged immobility

A lack of physical activity is a risk factor for hip and vertebral fractures. Limited mobility, so that the person cannot leave home or do housework, may be associated with, and compounded by, low or no exposure to sunlight and subsequent vitamin D deficiency. The inability to rise from a chair without using the arms (a marker of loss of lower extremity strength and power) is associated with an increased risk of minimal trauma fracture (refer to Section 2.3).

Poor balance

Poor balance increases the likelihood of a trip, slip, or fall and is a risk factor for hip and vertebral fractures. Balance training in isolation does not improve BMD, although it can reduce falls risk (refer to Sections 2.2 and 2.3).

Smoking

For both women and men, smoking is a moderate risk factor for vertebral and non-vertebral (including hip) minimal trauma fractures. Although a dose–response relationship is unclear, smokers generally have a higher fracture risk than non-smokers.

High alcohol intake

Based on general health advice, the National Health and Medical Research Council (NHMRC) currently recommends women and men should drink no more than 10 standard drinks a week and no more than four standard drinks on any one day.⁶ In addition to increasing falls risk, high alcohol intake appears to have a deleterious effect on bone-forming cells (osteoblasts), although the specific mechanisms are unclear.⁷

Vitamin D and calcium levels

Suboptimal dietary calcium intake and vitamin D deficiency are important public health problems in Australia. Vitamin D deficiency is associated with a higher risk of falling in older people. Routine screening of serum vitamin D levels should not be conducted. Testing should be restricted to those with suspected or proven osteoporosis, conditions or medications known to decrease vitamin D levels, deeply pigmented skin or severe lack of sun exposure due to cultural, medical, occupational or residential reasons (refer to Section 2.1).

Co-existing medical conditions

Co-existing medical conditions include those that increase bone loss or lead to lower BMD at an earlier age, such as rheumatoid arthritis, Type 1 and 2 diabetes, Cushing syndrome (endogenous or exogenous), hyperparathyroidism, hyperthyroidism (or thyroxine excess), chronic kidney disease, chronic liver disease, premature menopause, male hypogonadism, coeliac disease, inflammatory bowel disease or other malabsorption disorders. These conditions are associated with an increase in the age-specific risk for osteoporosis and minimal trauma fractures.

Pharmacological risk factors include medications that cause bone loss (e.g., ADT for prostate cancer or aromatase inhibitors for breast cancer; refer to Section 5.2).

Medications associated with increased risk of minimal trauma fracture particularly include prolonged glucocorticoids (at least four months cumulative prednisone or equivalent prednisone dose ≥7.5 mg per day). However, other medications associated with increased fracture risk in population-based studies should be considered, such as excessive thyroid hormone replacement⁸, selective serotonin reuptake inhibitors⁹, proton pump inhibitors^10,11, some antiepileptic drugs^12,13 and certain antipsychotics^14,15. However, it can be difficult to distinguish medication-related effects on bone health from the effect of the underlying condition that required their use.

• Any postmenopausal woman or man aged >50 years that sustains a fracture after minimal trauma (fall from standing height or less) should be considered as having osteoporosis.
• Bone densitometry can exclude pathological causes of fracture, although it is not always required following hip or vertebral fracture.
• BMD is helpful for risk stratification and provides a baseline from which to assess pharmacotherapy response.
• Patients should be assessed for possible vertebral crush fractures if there is well-documented height loss of ≥3 cm (measured by stadiometer), kyphosis, or unexplained back pain. A lateral thoracolumbar X-ray should be performed. If vertebral crush fractures are detected, bone densitometry (DXA) is recommended to determine BMD at the hip and spine.