What have they seen on my son's x-ray?

[learntojive]

My 13 year old son has been limping for a few months now, not profound but noticeable to me.
I think it's coming from the hip, my husband thinks the knee. I took him to the Dr's who sent him for x-rays of both hips and knees and now I have had had a letter saying they are referring him on for ultrsound tests although they didn't elaborate which is a bit worrying.
What could they have seen on the x-ray and what does the ultrasound do? I've only heard of them in conjunction with baby scans.
He's generally fit and well and doesn't have any pain. I had a congenital dislocation of the hip as a baby which resulted in some arthritus (just in that joint) and eventually a hip replacement at 40 but I don't think any of this is hereditary is it?
Thanks in advance if anyone can give me some advise

[redcrx]

maybe they havnt seen anything, which is why they want to ultrasound to look closer.

[jednbutter]

Dont worry its only a precaution.

[Sqad]

X-Rays have excluded a bone disorder.
So........what about a soft tissue (muscular or ligamentous disorder) and an ultrasound may well be helpful

I must say, that in my opinion an MRi might have been more helpful.

Don't worry it is "no big deal"

[learntojive]

Well the appointment came through quickly so we'll find out on Monday. Thanks for putting my mind at ease a bit x

[Mamyalynne]

Keep us informed ltj we do worry so don`t we.?