One diagnosis that comes to mind is Legg-Calve-Perthe's disease. This a disorder of boys aged about 8-10 of unknown cause, and involves 'aseptic necrosis' (lack of blood supply causing degeneration) of the femoral heads (top of the leg bone that fits in to the hip). This causes hip and/or knee pain bilaterally. One can see some joint space widening on plain xray but ,ay not. MRI should reveal the diagnosis and should be done as soon as possible. Infection in the hip joint should always be considered and excluded. Pain in the hip and lateral leg area can come from a pinched nerve ni the lower back and this can be tested for clinically, if suspected an MRI of the lower spine is indicated.
A problem in the hip can cause pain in the knee because of the similar sensory innervation. Other that this fact there is no primary neurological diagnosis to be considered.
If it has not already been ruled out, you might want to consider the possibility of ankylosing spondylitis. This is a type of arthritis that often affects the hips and the knees. It is more common in men than in women, and can begin in childhood, often in children around your son's age. The specialist you would see about ankylosing spondylitis would be a pediatric rheumatologist (who could also help you will out other rheumatological diseases).
Good luck finding a solution. I hope your son feels better soon.
Thank you for your responses. Do you know if arthritic symptoms can come and go in such short periods of time, and present with no noticeable swelling, heat, or redness? Also, will an MRI show arthritis? Does it make a difference if he is having the problem during the test?
Thankfully, this round is over, and he is back on his feet. I hope we figure this out soon!
I also agree that your son may have Ankylosing Spondylosis. As stated it would be best to take your son to a Pediatric Rheumatologist. They will take many blood test's and probably X-Rays. I also have very painful hips and pain in my left knee. I am a 40 year old female and I have osteoarthritis & Bursitis in my hips. If you do some research on the internet, you can find out exactly where the bursa is in the hips. The bursa is on the outside of the hip joint and if you press on that particular spot and it is extremely painful to your son, that could mean that he also has bursitis. My daughter also suffers with this. She got this from running a mile in platform sneakers in school. I was very upset with her gym teacher for allowing this. She did go to physical therapy and the therapy has really helped her. I also have arthritis in my left knee and it is very painful even to the touch. I am also sorry to hear that you son now has asthma. I was born with this and have suffered with it through out my life. But this can be controlled through medication's. Sometimes it does take some time to find the right medication that will work for him such as preventals and asthma attacks. Singulair, Advair and Albuterol have worked for me.
I do pray that the doctor's find the cause of your son's pain and he gets some relief.
Yes, Arthritis usually does show up on an MRI. My arthritis in my shoulder's and neck has showed up on my mri's. My hip's and knee arthritis showed up on an x-ray as that was the only testing that I had on these area's. Also I have extreme episodes of the swelling and pain and after a couple of weeks it will get somewhat better. But I believe that my meds also help in that area as I take anti-inflammatory's and Omega-3. I don't see as to how it would make a difference during his test whether he is having his problems during it. If he is inflamed more during the episode, this will also show up on the mri. But he may be more uncomfortable during the mri if he is having an episode as it will be harder to stay still.
I am happy to hear that you son is feeling better at this time. And I wish him luck during his mri. If you need any more info, you can email me at ***@****.