Medications such as Fosamax and Actonel have been around for a little while and are generally considered appropriate treatments for osteoporosis.
PTH injections are a relatively new thing, I suspect. I was not aware that they were being done. PTH works to increase calcium resorption from bone (taking the calcium out of bone) so I don't really understand how this would help. Raising PTH levels would lead to decreased calcium supplies in bone-the opposite effect of what is desired.
My advise to you would be to discuss this possible treatment with 1) a doctor that is familiar with and has used this treatment (you don't want to be the first one to try it out) and 2) an endocrinologist who understands the mechanisms of PTH and calcium homeostatis very well. This will give you the best information to make an informed decision.
Advice and opinions given are based on the information provided and must not be considered an official medical recommendation. The limitations of the internet prevent an appropriate evaluation. Always consult your doctor if there is concern.