Fullkerson procedure

I am a PT and currently treating a pt who had a Fulkerson procedure (9/04), he only came to the clinic 4 mos after the procedure, although we were able to increase free ROM without pain and inc strength. he still has bad patellar grating and pain upon wt bearing and flexing it. partial squats and lunges is just so difficult. I need some input. he's a high school student and would really want his back life. intervention was delayed sec to insurance issues. thank you very much