I am looking for pain relief from bone-on-bone osteoarthritis. I recently had fusion surgery in the L4 disc.

The surgery I had that was fusion of the L4 screwed into my spine, held only for a few weeks. My bones are so soft that the screws would not hold. I have severe stenosis in my lower spine and I am only able to stay on my feet for about 10 minutes before it seizes up and I need to bend over. We are scheduled for vacation in a couple of weeks and I'm worried I won't be able to walk very far before I give out. I take the ibuprofen and tylenol, but this doesn't make a difference. I have had physical therapy but it doesn't last at all. Please let me know if there are any medications I can take to keep my back from seizing up and I'm able to walk farther. Thank you so much.