17 years knee pain, may have fallen during volleyball, twisted this a day later and a few days later its locked up in pain. Nothing in the X-ray, just did a MRI, Dr. Said 4% fliud, nothing to really drain. Did a cortisone shot 5 days ago. Alot of pain still and locked straight for 4 1/2 weeks. P.T. twice a week and P.T doc said something is wrong. What do I do.