MRI neg 4 Meniscal tear. No internal derangement. Some popping, arthritic chges, bone spurs. PT 6 wks no relief 4 joint line pain. What is happening?

You have the answers. You mentioned arthritic changes, popping, bone spurs... these are all reason to have pain in the knee with even mild osteoarthritis. If you are not better with PT, I would consider maybe a Synvisc/Euflexxa injection series. Avoid steroid injections if possible. Also lastly you could look into stem cell options like Regenexx. Check out regenexx.com.