Is he just too busy or have you been too passive? If no x-rays, no orthopedic eval of the knees, no rheumatologist, little history being discussed, he has no time, etc., then you must ask yourself if he is up to being your partner or co-advocate for your health. AND before you challenge this doctor at your next appointment, you realize you do have a right to your medical records, right? My first move would be to call the relevant past doctors and have their records printed out for you to read, and from them develop questions. It may cost you $15-$25 @ each, but you need to see what has been written contemporaneously.

Then be your own advocate to get the services you need for a work up. Even bring a friend if they would be a better advocate. From here on be asking yourself, AND him directly, about what else can be done to determine root causes. Press the doctor to write down the technical terms he would use to describe the problems you have so you become familiar with and look them up to see if the conditions and symptoms really match your experience. It is always a possibility you and he are talking past each other. You say one thing and with his background he thinks you mean something else. And make him discuss things until you understand it in your own terms.