I was 75 a few weeks back, and don't really consider myself elderly as I am generally fairly fit.

However I have younger friends who are physically in far worse physical shape than me, so I consider myself lucky.

I think each case should be considered on its merits.

If the person who has fallen seems to be OK and can get up again and seems to be compis mentis, then there is probably no need for an ambulance.

On the other hand there have been reported cases of elderly people falling on the pavement, and in one case the daughter claimed to be a nurse, but left her mother on the pavement whilst waiting 3 hours for the ambulance, as she did not want to move her mother in case there was hidden injuries.  The poor woman died, presumably of hypothermia, whilst her only injury was a sprained wrist! 

My view there is that if you are able to make an assessment that there is little apparent damage elsewhere, then get the elderly person inside to wait for the ambulance if at all possible, rather than let the person die on the pavement due to hypothermia!