Osteoporosis and bone density tests

Wonder if it's time for you to have a bone density test? Bone density tests (also called bone mineral density tests or bone scans) evaluate the strength of your bones by measuring the bone density of a small part of your spine and hip bone. Knowing the strength of your bones can help your GP recommend prevention steps and osteoporosis medication, if needed, to prevent bone loss and fractures.

Who should have a bone density test?

Your GP will take a medical history to help decide whether a bone denstity scan might be appropriate for you. The following factors may be discussed to assess your risk of osteoporosis:

• History of previous fractures or falls.
• Age is particularly relevant if you are post- menopausal.
• Maternal history of osteoporosis or fracture
• Ethnicity (white people have a higher risk of osteoporosis)
• Medical conditions (certain diseases increase your risk of fractures and bone loss such as rheumatoid arthritis or problems with food digestion such as coeliac disease)
• Heavy smoking and alcohol consumption
• Long periods of inactivity
• Low body mass index (19 or less)
• Inadequate diet

After taking a history the GP will normally decide whether a bone scan would be appropriate for you.

What types of bone density tests are available?

There are several different machines used to measure bone density. "Central" machines measure bone density in the hip, spine and total body. "Peripheral" machines measure bone density in the finger, wrist, kneecap, shinbone and heel. Here are some of the different types of bone density tests:

• DEXA (Dual Energy X-ray Absorptiometry) measures the spine, hip, or total body.
• PDEXA (Peripheral Dual Energy X-ray Absorptiometry) measures the wrist, heel or finger.
• QUS (Quantitative Ultrasound) uses sound waves to measure density at the heel, shinbone and kneecap.
• QCT (Quantitative Computed Tomography) is used to measure the spine, but can be used at other sites.

The best test or “gold standard” which provides the most accurate and reliable results is the DEXA scan and is by far the most common technique used in the UK. As well as the scan your GP might do a variety of blood or urine tests to check you calcium levels and rule out common disorders that could lead to osteoporosis or cause conditions which resemble osteoporosis.

With the information obtained from a bone density test, you and your GP can decide the necessary prevention or treatment steps that are best for you.

What's the purpose of osteoporosis treatment to increase bone density?

The real purpose of osteoporosis treatment is to decrease the likelihood of future bone fractures or to prevent bone fractures in people at risk. Bone density scans are also used to monitor the effectiveness of osteoporosis treatment.

It's important to note that even if bone density deteriorates during treatment, it is quite likely that the patient would have lost even more bone density without treatment.