is a non-cancerous growth of the bone. Usually it does not cause much pain unless there is a fracture
. I suggest you also get a plain x ray
of the knee or if possible a CT scan
. Also please contact an orthopedics specialist. An X-ray can help in characterizing the lesion better. Sometimes the pain might be due to a problem somewhere else but felt at the knee. This is called Referred pain
. Again, an orthopedics consultation would help you better as to what the cause is and what investigations and treatment you need to undergo.
Hope I could be of help. Best wishes.