Results of bone density test determine follow-up testing
BY KEITH ROACH, M.D.
DEAR DR. ROACH: I am 76 years old and have had a bone density test every two years for the past 12 years at the recommendation of my physician. Every test has shown bone loss in my left hip, which is the result of a childhood case of polio. My physician has also pressed me to take Fosamax, which I have strongly resisted because of the unpleasant side effects.
I have been lectured to repeatedly about the dangers of falling. She said one out of three women currently hospitalized in the U.S. is there because of a broken hip. Recently, another physician looked up my test results and pointed out to me that the bone mass measurement in that hip has been virtually unchanged over the years. She said she thought a test every two years was excessive and therefore unnecessary. Given these two extremes, what would you recommend I do? — J.S.B.
ANSWER: Hip fractures are very dangerous, and medications like alendronate (Fosamax) reduce the likelihood of fracture when given to the appropriate person, which is any person, male or female, with a high risk of fracture. Fracture risk is best estimated by the FRAX score (sheffield.ac.uk/FRAX/), which uses bone density and other parameters to help doctors and patients decide whether taking medication is appropriate. I would strongly urge you to get this done and look at the result. Compare that risk against what it would be with medication. For people at low risk, the benefit of medication is small, but if you are at high risk, there is likely to be a large benefit to taking medication.
Your first physician must have been mistaken. Hip fractures account for less than 1% of hospital admissions. Perhaps she meant among the patients she was taking care of right now.
If your fracture risk is high enough to take medication, your bone density is usually measured every one to two years. If not, the recommended follow-up testing frequency depends on your bone density score.
Given that yours has stayed constant, less frequent checks might be reasonable. On the other hand, a history of poliomyelitis seems to be a large and independent risk for hip fracture. This is partly due to increased fall risk, but partly due to the effects of accelerated bone loss in people with less muscle strength, which is universal in the affected limb of poliomyelitis.