Can you define "bad hip" in a bit more detail? Does your rottie have osteoarthritis or hip displaysia? In either case, I would go with rimadyl or deramaxx as an anti-inflammatory/ pain relief medication. For any joint issues, MSM, glucosamine and chondroitin can help the soft tissues of joints stay healthy longer. These substances won't repair already damaged tissues, but can keep them going longer. Have a talk with your vet about dosages for your rottie.
In my personal experience, I've found deramaxx to be the most effective medication for arthritis in my dogs with no side effects. However, it's more expensive than rimadyl, which worked just about as well. We used rimadyl until it no longer made a difference and then switched to deramaxx. I'm not at all familiar with novox, but hopefully another member can comment on that one. Etogesic is another similar med, but every dog I've tried it on ended up with vomiting and diarrhea, so it was out of the question.