16 month old sudden tiptoe gait

My sixteen month old woke up several days ago unable to stand.  After several minutes of fussing and attempting to stand, he was able to regain his balance.  However, he was was walking with a limp and not putting his weight on his right leg.  This is a baby who took his first steps at 9 months and has never had ANY issues with walking or movement of any kind.

We immediately took him to the pediatrician who thought it was most likely toxic synovitis and was inflammation of the hip joint.  She recommended we watch it for a few days.  There were no changes.  Today we went for x-rays of the hip, foot and ankle, and all results were negative.  His condition has not changed or improved in 4 days.

Everything I have read indicates he has unilateral tiptoe gait - but WHY?  And, why would it have happened so suddenly?  Currently, the doctors just want us to keep waiting to see what happens, but I am so worried that this is something neurological.  My main concerned is that it literally happened overnight.  My baby seems completely oblivious to the change in his walking - he shows NO pain and it has not slowed him down one bit.  Anyone have advice or similar experience?  Thanks!

[salmac]

We just went through the same thing you have described about with our 16 month old daughter...we are very concerned that this may be something serious...I noticed that you put this post up a few months back and was wondering what happened with your son...what was the diagnosis? Is he back to normal again?

[Caliber2005]

Hi,
How is your son now?
Are there any other symptoms apart from this? Since he has attained his milestones normally, does it seem that he is regressing on his milestones?
I think your child needs an urgent neurological evaluation. Evaluation for any lower back injury and for any toxic causes of neurological impairment. Also, he needs evaluation to assess for regression of milestones which indicates neurodegenerative disorder.
You need to consult a Pediatrician and a Neuro-pediatrician at earliest.
Keep me informed about the disease progression.
Hope this helps.
Bye.