Hi there Iliastolos,
I don't know of any articles for your specific topic, but here is a link to a post op rehab study in children with CP, although is quite specific to outcome measure comparisons. Anyway, maybe it'll help you.
Comparison of the Gross Motor Function Measure and...[Dev Med Child Neurol. 2000] - PubMed Result
In case that the link doesn't work, the article title is:Comparison of the Gross Motor Function Measure and Paediatric Evaluation of Disability Inventory in assessing motor function in children undergoing selective dorsal rhizotomy
A very good web page to find information about pediatric physio is,
CanChild Centre for Childhood Disability Research
I hope this helps. Good luck on your search.