Step 4: Read and complete the decision guide to learn more about your symptoms.
To recap, you are age 45 or younger, no other joints are bothering you besides the sore knee, but there is swelling in the sore knee.
There's just one more question. It has two parts:
1) Do you have locking of the knee? That is, are there times, even briefly, when you cannot move your knee at all?
2) Are there times when your knee will not support you?