My baby has hydrocephalus and his back is open he can't move his legs a surgery was operated on his brain will he be able to walk?

Hydrocephalus: A combination of both hydrocephalus and spina bifida is not good. The ability to walk is related to the level of neurological injury and in this case it appears to go to the hips. Independent walking with braces very unlikely but may change in the future as more mechanical devices are designed to assist in walking.

Meningomyelocele: For meningomyelocele , it depends on the level of the defect and the affected region if a child can ever walk. Good signs are moving the legs and having bowel and urine control.

Maybe/not: The open back exposes nerve elements that control the legs & they are often never going to work right. If the child survives the multiple procedures to deal with the open back & shunt the fluid buildup in the brain, the outcome is guarded. Some may have the ability to walk with assistive devices but later abandon them to use a chair (more speed).