Although it is less common than common osteoporosis, there have been some reports of regional migratory osteoporosis that have been described in the medical literature. However, intravenous bisphosphonates are not usually given as the first line of treatment -- they are frequently prescribed after other treatments have either failed or not been tolerated. I haven't heard of them being given to someone with a normal DXA scan (the test which is considered the gold standard for diagnosing osteoporosis.) If you and your family have doubts about this physician's recommendation, perhaps you are interested in seeking another opinion from a different specialist before you embark on such a remedy. In the meantime, do take steps to protect your ankle and how much weight you bear on it. Best of luck to you.

Just a quick clarification on my earlier answer -- I mentioned I hadn't ever heard of intravenous bisphosphonates being used on a person with a normal DXA scan -- I should have specified, to treat osteoporosis on a person with a normal DXA scan. Medicines such as Reclast (zoledronic acid) are also used to treat conditions unrelated to osteoporosis (often associated with cancer) and such an individual might have a normal DXA but take the medicine for the other problem. Of course, that's unrelated to your question, but I did want to be as accurate as possible.