### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Hi! Yesterday I landed directly on my knee cap while playing softball. I was able to walk off without an issue and I applied ice right away. I kept it elevated and straight to help with swelling. Due to my concern, I went to the hospital after the game. They took X-rays and nothing was wrong. No sign of broken bones or even blood filling the joint, which was a sign of any tear in a ligament. No bruising has occurred at all. The doctor then twisted my leg two ways, pushed it, and pulled it and nothing hurt. She said I just had a nasty fall and to stay off the rest of the day, elevate and ice. So I went to bed and I woke up and could barely move the joint, stiff as a board. My sister is a PT and so she said to prevent any stiffness and to decrease swelling, I had to do easy knee exercises to keep mobility and to walk a good bit. It feel much better but now my knee feels kind of loose and unstable. However, she said it may be due to the swelling. Suggestions? Should I go back to the doctors for an MRI? They tested me and checked for signs but said I should be perfectly fine

### output:

Dear patient If your knee feels unstable and loose after fall possibility of ligament tear is highly likely. Since your X-ray is normal I would advise MRI of involved knee to confirm diagnosis.  Take visit to radiology center nearby you and get it done. If it shows ligaments tear you need to consult expert arthroscopic surgeon nearby you and get yourself examined.  If report is normal you need not worry and wear knee cap for 2 weeks and then start physiotherapy.  All the best.