I have had Synvisc injections in my left knee now for 2 years, each series of 3 shots have lasted me 12 mo each, but now. Aetna won t cover Synvisc, but want me to try, Monovisc or Euflexaa. I feel that I have had good success with Synvisc. I like the idea of being derived from the rooster comb and feel it is btter for my knee than cortisone, so what is Monovisc and Euflexaa, are they a type of cortisone? Ron