Thanks everyone for your responses.
Prolotherapy is often used for micro tears of the Achilles. Essentially they make a whole bunch of micro holes in the Achilles with a needle and glucose solution. The body then creates an inflammatory response and sets about healing the area with scar tissue and voila the Achilles feels better. As you might imagine this inflammatory response could easily become systemic (or everywhere) in an individual with AS.
They will only inject cortisone if there is a bursa to inject it into. I didn’t have one.
I have been trialing Sulphasalazine and have doubled my biologic agent for the past few weeks and nothing is helping.
I see my Rheum next week. Have been doing physio and working out in the hot pool (muscle strengthening). Getting very frustrated. Feel like if I can’t walk my quality of life will really be affected.