Degenerative hip disease in 1 year old cat

A few months ago, I adopted a pair of sister calico kittens.  I was told they were 7 months, the paperwork says 10, moths os we are saying she is a year old.  A few weeks ago I noticed her limping. The next day she wasn’t walking so off to ER vet we go.  No obvious break or wound.  They felt she pulled something and would improve.  They gave her an anti inflammatory and advised if the limp didn’t go away to see her vet.  It appeared to work till this past Saturday,  again with a very slight limp progressing to non weight bearing so off to the vet we went.  X-rays were done and we are awaiting the official results.  Vet states in his opinion she has degenerative hip disease which is uncommon in cats her age.  He will wait for the final X-ray results but is going to refer us to an ortho specialist.  Meanwhile another shot was given and two pills for the next two days. That’s it.  She is still severely limping.  Yes I googled and I’m worried.  His nurse said that even if it’s the best scenario she has arthritis and long term pain management techniques don’t do well in cats.  Surgery could be one or multiple and may or may not work, depending on the extent of the current x-ray results. 

Anyone have ave experience with this and their cats?   Nobody seems to have any solid options and I’m trying to be proactive.