Knee Injury?

I am 24 yr. old female and Saturday I was on my knees cleaning and when I went to get up my left knee locked up on me and I couldn't bend it. When this happened it was extremely painful and when I finally straightened my knee there was a loud pop.  After that the back of my knee seemed alittle swollen and was sore for the rest of the day and most of Sunday. I had some tenderness and some instability going up and down stairs. I went to my doctor to get it looked at yesterday however my knee seemed fine and I didn't seem to be having anymore pain. So it was hard for her to diagnose what was wrong. Plus with her not being an orthopedic surgeon she didn't exactly know how to test the knee physically for any possible damage. So I was sent on my way with instructions to keep icing it for a couple of days, take some Ibprofen for any pain or swelling and to get a knee brace for extra stability. And if any further pain persists or my knee locks up again to call her and she will refer me to a physical therapist? So I'm wearing the knee brace today but my knee seems to be hurting more now with it on. Is this normal? Also, last night when I bent my knee to take my boots off my knee almost locked up on me again but instead just popped and went back to normal. Should I be asking to be referred to an Orthopedic surgeon for further testing or should I just take this as a minor injury and continue with the treatment suggested? Thanks in advance for any feed back!

[JainMD]

Hi,
I appreciate your concern towards your health, but you should not take this lightly and should make an attempt to diagnose the injury.
You should be seeing an orthopedist as early as possible and get imaging study done to see for any injury. Imaging study should be MRI to look for soft tissue pathology.
When any patient complains of “knee pain,” the initial differential diagnosis in most of the cases includes: Osteoarthritis, Ligament damage, Meniscus damage or Patello-femoral disorder.
Your symptom of pain at the joint line is the result of a collateral ligament or meniscus problem (or both) until proven otherwise.
Your symptom of sudden pain, then hearing a pop and swelling suggests that you have ligament injury. If the patient has a ligament injury, the patient will report a deceleration injury or twisting the knee that led to immediate symptoms of swelling and pain. In fact, 30 to 50% of patients will report actually hearing a “pop” at the time of injury.
Your symptom of locking and catching are characteristic of meniscus injuries.
Are there any positions that make your knee more or less comfortable?
What is the quality of your pain (sharp, shooting, dull, etc.)? Have you tried anything to help the pain and, if yes, has that been successful?
Have you ever had surgery on your knee? Do you have any hip or ankle pain?
Keep me informed if you have any queries.
Bye.