<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, Ive been experiencing knee swelling, cramps and spasms, leg stiffness and weakness, and Ive noticed a lump on my knee. What could be the problem?  <response>: Based on your symptoms, it sounds like you may have torn your knee ligament or meniscus. Well need to do some imaging tests to confirm the diagnosis and determine the best treatment plan. 