If your knee pain and discomfort has reached the stage where you want to talk to your doctor about possible surgical solutions, your GP can recommend an orthopaedic surgeon for you to discuss this with. If you have your own surgeon in mind mention this to your GP.
In order for your GP to appreciate how severe your knee condition is, make a list of how the knee pain has impacted your life. For example, how does it affect your sleep, your job, your hobbies, driving, interacting with your family etc.
Creating another list showing all the ways you have tried to relieve the pain will help your GP appreciate your condition. For example, home remedies like hot/cold packs, over the counter pain medicines like paracetamol, alternative medicines etc.
It may be useful to also have a list of other questions you have and possibly take a pen and paper to take notes, including finding out where you can get more information.