15 yr old facing another spine surgery

I have posted before regarding my son. quick history due to scoliosis he had a spinal fusion surgery done at johns hopkins june 1st 2011. Since the surgery he complained of chronic back pain and eventually we ended up at a pain management clinic and he is now using a tens unit which does help with the pain but he cannot wear it constantly so he still has periods of pain and the drs do not want to prescribe narcotic painkillers due to fear of addiction. He was prescribed celebrex but it didnt help.

We went for check up with ortho surgeon last thursday at johns hopkins and new xrays show that the 5 vertabrea at the base of his spine before where the rods start are bowing out and looks like a backward c. Thats the cause of his pain and the dr gave him the option of dealing with the pain or fusing those vertabrae-well my son chose the surgery. I was in so much suprise i really didnt ask any questions and have been waiting to hear back from the drs to get my questions answered. So if anyone has any experience with this i want to know how will this affect his mobility? im also wondering how long he will be out of school and how long i should plan to be off work with him as i am the only person that will be caring for him.

The surgery is sched for oct 21st-5 days before his 16th bday. So much for a sweet 16 for him. Thanks in advance