Diagnosis of Osteoporosis

Signs of osteoporosis

There are often no symptoms, with osteoporosis often being called the ‘silent disease’.¹

As bone loss itself does not cause pain or other symptoms, a diagnosis of osteoporosis can come as a surprise for many after a fairly minor fall or injury.² This can include a wrist fracture from putting out an arm to stop a fall, or a broken hip from a fall.³

In addition to the above, spinal fractures may also present with one or more of the following signs:^3,4

Unexplained back pain and muscle spasms - A vertebral fracture can occur in patients with osteoporosis from minor activities, such as bending down, causing severe back pain.

A curved spine or change in posture - Multiple fractures can cause the spine to curve. As this can occur slowly and over a long period of time, it may not be initially noticed by patients.

Height loss - When vertebral bones weaken and begin to collapse, height loss can occur, even without a noticeable curved spine.

Diagnosis guidelines

The following organisations provide guidance on the diagnosis of osteoporosis:

World Health Organisation (WHO)

The World Health Organisation (WHO) defines osteoporosis as bone mineral density (BMD) that is lower than 2.5 standard deviations (SD) below the young adult mean. The gold standard for assessing BMD is dual-energy x-ray absorptiometry (DEXA).⁴

NICE Guidance

NICE Technology Appraisal Guidance 160, states that osteoporosis is defined by a T-score 17* of -2.5 standard deviations (SD) or below on dual-energy X-ray absorptiometry scan (DEXA).⁵

Regarding those aged ≥ 75 years, the guidance states an assumptive diagnosis of osteoporosis may be made if DEXA is unfeasible, or clinically inappropriate.⁵

*T-score relates to the measurement of bone mineral density (BMD) using central (hip and/or spine) DXA scanning and is expressed as the number of standard deviations (SD) from peak BMD.

NICE suggests:⁶

Considering assessment of fracture risk in all women aged 65 years and over and all men aged 75 years and over.

Patients who are treated with medication that has a negative effect on BMD should also be assessed for osteoporosis with a DEXA scan (e.g. sex hormone deprivation for treatment for breast or prostate cancer).

In people under 40 years old who have a major risk factor (e.g. history of multiple fragility fractures, major osteoporotic fracture, or current or recent use of high-dose oral or high-dose systemic glucocorticoids), measure BMD and assess their fracture risk.

FRAX

DEXA is just one element of assessing osteoporosis risk in patients. New approaches are now developing, such as considering a person’s absolute risk of fracture.⁷

One of these approaches is a fracture risk assessment tool called FRAX^TM which is used to identify those most at risk of fracture.⁷

The FRAX^TM algorithm provides a 10-year probability of osteoporotic fracture, with or without BMD data. The simple algorithm allows the clinician or patient to input risk factors to calculate fracture risk.⁷

The tool is similar to the risk factor calculators developed to establish an individual’s risk for cardiovascular health issues. It also uses a range of applicable factors to calculate the risk such as age, sex, smoking habits, alcohol use, weight, height, glucocorticoid use and history of rheumatoid arthritis, fractures and osteoporosis, and BMD if available.⁸

One of the advantages of FRAX^TM is the potential use within primary care to help with the prevention of fracture and subsequently the prescribing of suitable treatments.⁷

A clinical assessment of osteoporotic risk factors alongside bone mineral density measures can help identify those who will benefit from intervention and treatment which can then potentially reduce morbidity and mortality associated with osteoporosis.⁹