Beyond Bone Density

Frax relies on a long list of variables that influence risk: age; sex; weight; height; previous fractures in patients and their parents; current smoking status; prior chronic treatment with glucocorticoids; a diagnosis of rheumatoid arthritis (not osteoarthritis); a diagnosis of secondary osteoporosis (bone loss from a trauma or illness); level of alcohol consumption (more than three daily glasses of wine, or the equivalent, increases the likelihood of a break); and low bone mineral density at the femoral neck (a frequent site of hip fracture, just below the bony knob of the upper thigh bone).

After patients fill out a simple online survey, the FRAX calculator weights the risk factors according to the most recent data and spits out two numbers—a 10-year probability of hip fracture and a 10-year probability of any major fracture of the hip, spine, forearm or shoulder. Those numbers are a rough guide, the WHO emphasizes, and should not substitute for a doctor's clinical judgment about a particular patient. Someone who smokes and binge drinks frequently and has already had a painful fractured hip, for example, is probably more likely to suffer another broken hip than a light smoker and drinker of the same age who has had a painless vertebral fracture that could barely be detected by x-ray. Even so, the FRAX calculator would give those two people the same score.

Despite FRAX's flaws, Cummings says the tool is an improvement in risk prediction because it puts bone density in proper context as “one factor—an important factor but just one factor—in your likelihood of fracture.” Bone health experts currently recommend a baseline bone scan and FRAX calculation around age 65. And anyone—male or female—older than their mid-50s who fractures any bone in the absence of a car accident or similar trauma should be evaluated for osteoporosis and considered for bone-building drugs. Too many emergency room doctors today, Seibel says, are still just setting the broken arm or wrist and sending the patient home. After late middle age, experience and statistics confirm, there is no such thing as a simple fracture.

SCIENTIFIC AMERICAN ONLINE
Comment on this article at ScientificAmerican.com/aug2012

4 Comments

1. 1. dcorliss 02:06 AM 7/22/12

   ... "in a group of people with the same bone mineral density, some got fractures and others didn't"
   
   Any ideas as to the actual causal mechanism for fracturing? Could there be some sort of micro-crack development due to abnormal osteoclast/osteoblast functions, thus allowing the creation of stress concentrations? Stress concentrations are geometrical anomalies, such as sharp corners, cracks, etc. which can cause a multiplication, or increase, of the otherwise normal stress levels within a structural member.

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2. 2. jgrosay 09:56 AM 8/7/12

   Evidence is conflicting regarding the Calcium supplements as a preventive measure for Osteoporosis, some point to increased cardiovascular events with Ca, recent work indicates that this would be negligible, benefits clearly overcoming any risk, but for sure it has been shown that as more hours you're standing, and also exercising, the higher the increases in your hip's bone density and the bigger the decreases of your chances of suffering a hip fracture is, hip fractures that are probably more dangerous than the vertebral fractures that usually induce only pain. Vitamin D supplements have also beneficial effects in other health issues, and as a matter of curiosity, there's even work pointing that the only intervention, at least in the elderly, that will improve overall health would be weekly Vitamin D supplements, every day dosing being less efficacious, and dosing with a longer time span from one to the other, specially once a year dosing, would be even detrimental.

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3. 3. jgrosay 09:58 AM 8/7/12

   Is wrist DXA the best approach for checking Bone Mineral Density or not?

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4. 4. ewcollins 09:19 AM 10/11/12

   I am a 60-year old male. I have osteoporosis, but I have never had a fracture.
   
   I could tell that something was wrong, so I asked two different primary care physicians if I could have a DXA scan. They both said, "No. You have no risk factors". Finally a third physician agreed with me and ordered the test. The results showed osteoporosis of the lumbar spine and osteopenia of the hip and femoral neck. I was 58 at that time.
   
   In my opinion, everyone (both male and female) should have a baseline DXA scan at age 50 (the same as is recommended for a colonoscopy). The first sign of osteoporosis should never be a fragility fracture.
   

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