I need a opinion i had knee surgery 1 year ago for plica resection i am still having a lot of pain what could it be? was told no arthrtis

Plica: Consider scar, synovitis, new tears of meniscal tissues, patellar maltracking, continued plica impingement. Check with your orthopedic surgeon.

Plica pain: Residual pain following knee surgery can be multifactorial: one of the more common issues would be a different source for the pain. This could include a radicular component from the lower back (herniated disc), hip arthritis, a more involved systemic condition that can affect the knee synovium such as an autoimmune condition or low grade infection such as lyme. A thorough work up is in order.

Meniscus.: You may have a meniscus tear. consult your surgeon to see if that's a possibility.