4 year old with knee pain

When my daughter was 2 1/2 she broke her leg when she bounced down on a trampoline. We think she had her legs crossed and bent under her when she landed (this from her 10 year old cousin). All the adults saw her bounce up, no one saw her when she landed until she started screaming.  She had a hairline fracture about 1.5 to 2 inches right below the knee on the front of the Tibia on her right leg. She had a recheck 6 months later and there were no problems in her growth plates and all seemed to be fine. Since then she has been waking up screaming and kicking with pain behind her knee right in the middle across the crease where the knee bends. She does this 2 or 3 times a month. There doesn't seem to be a pattern to it. Sometimes we have done a lot of walking, she has done a bunch of jumping, running, etc. And sometimes not. There is no swelling, redness or warmth to the area. It is always just the right leg and occasionally the area around her knee on her thigh also hurts. We mentioned this at her 1 year recheck and were told to wait and see if things get worse. We took her back a few months ago when there was no change. They took more x-rays and said the x-rays are fine. He said it could be growing pain and said they were usually in both leg though. But that she might actually be having discomfort in them both but because of her previous injury she could just be more sensitive to the pain in one leg so it distracts her from the discomfort in the other leg. He does have directions for bloodwork in her chart though. If it gets warm or swells we were to call immediately to have blood drawn, if not and it isn't better by the time she turns 5 they will do an MRI, but they really don't want to have to do one since it would require sedation. I usually agree, but at 3am when you have been massaging a screaming child for an hour, you just want to get to the bottom of it. She hardly ever complains about pain during the day, but a few times has. Then something distracts her and its all forgotten, so I am afraid that she has more pain than she says and is just too distracted during the day to let it interrupt her playtime. She knows I would make her sit down and be still. I have gotten her an another appointment to insist they run all the tests and just get it over with, but it is 1.5 months away. (Now thinking about that she will be a few weeks from turning 5 anyways) What could be going on with her knee and how to I treat it at home until we get to the bottom of this?

[margypops]

I have to say it as other parents may let their children on a trampoline ...No Trampoline , certainly not in a child of this age .However I am sure you have told your self the same many times , I agree it could be growing pains as the bones and tissues grow ,and that leg having been injured would be be more sensitive ., and growing pains do hurt more when the child is resting or after exercise .All you can do is wait to have further tests done to get some answers, did they tell you to give her any med to help the pain?