Not all fractures are equal. A young person breaking a wrist after a fall from a bicycle is one kind of injury. An older adult breaking the same wrist after tripping while walking is a very different story — that fracture is often the first visible sign of underlying bone weakness.
A DEXA scan after a fragility fracture is one of the most important investigations someone over 50 can have. It can change what happens next, including whether treatment is needed to prevent the next fracture, which is often far more serious.
What is a fragility fracture?
A fragility fracture is a broken bone caused by a force that would not normally break a healthy bone — typically a fall from standing height or less. The most common sites are:
- Hip — especially in older adults, after a fall to the side.
- Wrist (distal radius) — often the first fragility fracture, when someone falls forward and catches themselves.
- Vertebra — sometimes silent, discovered as height loss or back pain.
- Humerus (upper arm) — after a fall onto an outstretched hand.
A fragility fracture is the bone announcing itself. Even with a single such fracture, the risk of another one — particularly a hip fracture — rises significantly.
Why a DEXA scan matters after a fragility fracture
After a fragility fracture, three things are true:
- The bone has already declared its weakness. A DEXA scan now is partly to confirm the underlying cause and partly to establish a baseline for monitoring treatment.
- The risk of a second fracture is highest in the first 1 to 2 years after the first one. This is the "imminent fracture risk" window when treatment makes the biggest difference.
- Many people who would benefit from treatment never get a DEXA scan after their fracture. This is one of the biggest care gaps in orthopaedics worldwide. Asking for the scan is often what makes it happen.
When should the DEXA happen?
Arrange bone-health assessment promptly rather than waiting for the fracture to heal. The exact DXA timing depends on mobility, pain, fracture site, treatment urgency, and local access. The spine and unaffected hip may be measurable earlier; an injured or operated site may be unusable. Very-high-risk patients may need treatment before a DXA result is available.
For vertebral fractures, the affected vertebra is usually excluded from the spine measurement to avoid skewing the result.
What other tests are often done alongside?
A DEXA after a fragility fracture is usually paired with:
- Blood tests for calcium, vitamin D, kidney function, thyroid function, and sometimes parathyroid hormone and testosterone.
- A FRAX score — a fracture risk calculator that combines your DEXA result, age, sex, history, and a few risk factors to estimate your 10-year risk of major fracture. Helps decide whether treatment is needed even when the T-score is in the osteopenia range.
- Vertebral Fracture Assessment (VFA) — a low-dose DEXA image of the spine that detects silent vertebral fractures. Many centres add this when DEXA is done for fracture follow-up.
How is the DEXA different from a routine one?
The DEXA itself is the same scan. What is different is the interpretation:
- A hip or vertebral fragility fracture can establish osteoporosis clinically regardless of T-score. Other low-trauma fractures still indicate high risk and require assessment, but the exact diagnosis and treatment threshold depend on fracture site, age, secondary causes, and the guideline used.
- The conversation moves from screening to urgent secondary-fracture prevention, not just monitoring.
What happens after the DEXA?
Treatment makes the second fracture less likely
The strongest evidence in osteoporosis is for secondary prevention — treating people who have already had a fragility fracture. Modern medications reduce the risk of further fractures meaningfully, and the benefit appears within months. Waiting and watching after a first fragility fracture is rarely the right call.
Your doctor will combine your DEXA result with your fracture history and FRAX score to decide on treatment. Options usually include:
- Calcium and vitamin D supplementation if deficient.
- Bisphosphonates (oral or annual IV) as the first-line osteoporosis treatment for most patients.
- Other agents (denosumab, romosozumab, teriparatide) for high-risk patients or those who cannot tolerate bisphosphonates.
- Falls prevention — physiotherapy, strength training, home safety review.
- A repeat DXA when it is likely to change management, using a valid baseline and the facility's LSC.
What if my T-score is not in osteoporosis range?
A T-score above −2.5 does not make a low-trauma fracture unimportant. Hip or vertebral fragility fractures can establish osteoporosis clinically; for wrist, humerus, pelvis, and other fractures, clinicians combine the site, trauma, age, DXA, and overall risk. Treatment may need to start before DXA when fracture risk is very high, so the scan should not become a reason for delay.
Will the DEXA hurt my healing fracture?
No. The radiographer will position you carefully and avoid putting weight on the injured side. The scan itself uses very low radiation, is contact-free during imaging, and is well tolerated even in patients recovering from fractures.
What are the important limitations?
DXA measures two-dimensional areal bone mineral density; it does not measure every aspect of bone strength. Arthritis, vertebral compression, calcification, previous surgery, metalwork, positioning, and differences between machines can distort results. Fracture risk must combine the usable DXA sites with age, previous fractures, medicines, falls, medical conditions, and—when appropriate—a validated risk tool.
A fragility fracture can justify an osteoporosis diagnosis or treatment assessment even when the T-score is not in the osteoporosis range. For monitoring, compare valid studies from the same facility and machine where possible, and only call a change real when it exceeds that facility's least significant change (LSC). The timing of another scan should be individualised.
Sources and further reading
- International Society for Clinical Densitometry: 2023 Adult Official Positions
- RadiologyInfo.org: Bone density scan (DXA)
Conclusion
A DEXA scan after a fragility fracture is one of the highest-leverage tests in adult medicine — it directly identifies people who would benefit from treatment to prevent a second, often more severe fracture. If you or a family member has had a hip, wrist, vertebral, or other fragility fracture after age 50, ask the doctor about a DEXA scan and a FRAX assessment. The window to act is the first year or two after the first fracture.