Opana worked well for me... But I have never had a med that works as long as it is supposed to! Have you ever tried Exalgo? It is hydromorphone instead of oxymorphone. I've done both but I'm on MS Contin for my extended release right now, it works well. Low dose ER meds only help to take the edge off so that the instant release works a little better. Maybe you should try a new IR like Roxie's, nucynta, or dilaudid. All have worked well for me at some point, but all meds work different for different people, you just have to try them all...
I also have rsdmalong with other things. It's very challenging.
My doctor tried me on Opana. Supposedly it works at a lower sose. Did nothing for me.