Kate, please do not write off the whole of the NHS because of one bad experience.
A bone scan is completely different from a cataract operation. It is not invasive, all it does is measure bone mass via low level x-rays. At your age, and you are young in outlook, it will tell you if your bone mass density (BMD) is where it should be.
There are no 'cures' but the results could inform you of how to be safe and not injure yourself.