When Debra fractured both a tooth and a bone in her foot within a year, she suspected something was wrong. However, it wasn’t until she consulted her doctor for brain fog and fatigue linked to perimenopause that bone health was discussed.
After learning that both of Debra’s parents had suffered osteoporotic fractures, her doctor recommended a bone density scan — a specialised X-ray — which revealed she had osteopenia, a condition characterized by reduced bone density that may have contributed to her fractures.
Bone density typically declines with age, making bones more fragile and increasing the risk of fractures from minor incidents, known as “fragility fractures.” In Debra’s case, she cracked her tooth while sleeping and fractured her toe after slipping.
Since osteopenia and osteoporosis often develop without noticeable symptoms, many people aren’t diagnosed until after a fracture occurs. However, bone density tests can identify low bone density and help prevent further deterioration.
Who should have a bone density scan?
Healthy Bones Australia recommends that men and women over 50 with risk factors undergo a bone density scan, though younger individuals with risk factors, like Debra, may also benefit. Risk factors include:
- Family history of osteoporosis
- Low calcium or vitamin D intake
- Certain conditions (e.g., coeliac disease, inflammatory bowel disease)
- Early menopause or low testosterone in men
- Use of specific medications (e.g., corticosteroids, cancer hormone treatments)
- Smoking, excessive alcohol, and physical inactivity
Due to the rapid decline in bone density after menopause, bone health expert Shoshana Sztal-Mazer advises all postmenopausal women to have a scan to establish a baseline.
Healthy Bones Australia also offers a survey to assess osteoporosis risk, which can be discussed with a doctor.
Is a bone density scan covered by Medicare?
A referral from a GP is required to access the scan, typically costing between $80 and $120. Medicare rebates are available for people over 70 or those diagnosed with or at risk of osteoporosis. Some people under 70 may also be eligible if they’ve experienced a fracture. However, inconsistencies exist: for example, postmenopausal women on estrogen-blocking breast cancer treatments aren’t eligible for a rebate, while men on testosterone-blocking prostate cancer treatments are. Healthy Bones Australia is advocating for these inconsistencies to be addressed and for the rebate age threshold to be lowered to 65.
How does the test work?
The standard bone density test is a dual energy X-ray absorptiometry (DEXA or DXA) scan, which measures bone minerals like calcium. The painless scan usually takes about 15 minutes and focuses on the hip and spine — common fracture sites. Higher mineral content indicates stronger bones.
Understanding the results
The DEXA scan provides a bone mineral density score and a “T score,” which compares bone density to that of a healthy young adult (a score of 0). Every point below 0 increases fracture risk by 1.5 to 2 times. A T score of -2.5 or lower indicates osteoporosis, while a score between -1 and -2.5 means osteopenia, as in Debra’s case. Treatment may involve medication, calcium and vitamin D supplements, and exercise.
A “Z score” is also provided, comparing bone density to people of the same age, sex, and ethnicity. It’s mainly used for younger individuals but can sometimes reveal other causes for bone loss.
Based on the results, healthcare providers can develop a management plan. Debra’s doctor prescribed hormone replacement therapy to address both her perimenopausal symptoms and bone health, along with vitamin D, calcium, and a tailored exercise regimen. Physiotherapists or exercise physiologists can create personalized exercise plans, with some visits subsidized by Medicare under a team care arrangement.
Limitations of bone density scans
While helpful, DEXA scans have limitations. Many people who suffer fragility fractures don’t meet the osteoporosis criteria based on bone density alone. According to bone specialist Ego Seeman, bone density scans detect only 20-30% of future fractures.
To improve fracture risk prediction, researchers are exploring 3D imaging of bone micro-architecture, which offers a more detailed picture of bone structure. Professor Seeman reports that combining bone mineral density with micro-architecture analysis can identify up to 70% of fractures over eight years.
Dr. Sztal-Mazer, who is also researching bone micro-architecture, says the ultimate goal is to find better tools to predict and prevent fragility fractures.
“We’re working hard to identify the most accurate surrogate measure to assess fracture risk,” she explains.
