hip subluxation/dislocation?

Question
My 12-year-old F Golden has developed rigid hocks and possibly subluxated hips.  Her back legs will completely splay out to the sides if her feet slip out from under her on a tile floor.  This is now also happening on carpet and she has to be helped up in these instances.  She now tends to lay or sleep stomach down with her back legs extended under her so that her feet almost reach her shoulders.  I think the hips may be subluxated/dislocated because the range of forward motion is greatly increased in her back hip joint.  But would she even be able to walk at all if this were subluxation?  Given her age, sugery is not being considered but I don't know how long to wait before considering euthanasia.  Last trip to the vet they wanted to do a lot of testing but I'd rather just let her age and treat her conditions palliatively.  She's healthy in all other aspects and very happy when on all fours.  I do fear that she will get cast down on the floow and be trapped while she is home alone.  Could this simply be arthritis and not subluxation?  She's received daily glucosamine and dog aspirin.  Thanks for your help.

Answer
I really feel your vet can better advise you on the arthritis and hip problems.  When to euthanize is a tough question.  I have a 14 year old Lab with cancer in her upper jawbone.  The vet has done what he could, can't remove it all.  For now she is much the same, just an inactive old dog.  She does still seem to be enjoying life.  She spends time keeping a careful watch out the front window.  She carefully inspects all the mailbox posts on the block on her daily walk.  She is still eating, although I am putting a little hot water on her chow to soften it.  When she quits eating and doesn't enjoy her walks, it will be time.  

So yes, continue the medicine, and even consider stronger pain killers from the vet.  When she is in pain all the time and never seems to enjoy anything, then it will be time.