David Undergoing not just 1 but 5 knee replacements I am sure takes a toll on your body. Post operative surgical pain can exacerbated several fold in patients with chronic pain on long term opioid regimens. This is because your body now is not only sensing the chronic issues but now experiencing acute pain from surgery, often time amplifying your pain. Patients with chronic pain often require increase amounts of pain medication compared to someone who does not As an anesthesiologist, I could not be happier that you requested a nerve block prior to your last procedure. This will definitely minimize the amount of post surgical pain. I suggest advocating for one prior to surgery again, even ask if having a short term nerve block catheter is an option. Also discuss with your Anesthesiologist the day of the procedure your concerns. Often times additional medications such as Lidocaine, Magnesium, and Ketamine infusions can be started during surgery to aid in post operative pain. Regardless you still need to take pain medications post operatively so you do not have to play catch up once the block wears off. Multi-modal pain relief will also aid in pain control at home, which will tie into the second part of your questions. Drugs like Lyrica and Gabapentin aid in neuropathic pain. Cymbalta, a SNRI, also has been approved for treating chronic pain. Continuing these on top of Tylenol, NSAIDS (Ibuprofen, Motrin, Naproxen), post-surgical prescriptions by surgeon will attack the pain on all fronts. It is very important though that you follow the instructions of your current doctors. Additionally it may be beneficial scheduling an appointment with your Chronic Pain Doctor prior to surgery to also discuss your concerns and post operative options.