I agree with the other posters.
On our trip in April, I was wearing a Fitbit that kept track of steps and miles. We were traveling with several people who were not regular walkers, do we took it a little easy for their sake. Even with that, we walked more than 5 miles a day - sometimes up to 9!
So, even if he is walking and is no longer in pain, he may not be up to walking at WDW.
I would see what the PT thinks as far as progress. You could either rent a wheelchair now and cancel if he doesn't need it or just wait until closer to the time.
See post 2 of the disABILITIES FAQs thread for information about renting at the parks and from off site vendors. Follow the link in my signature or look near the top of this board.
The park wheelchairs are adult with 20 -22 inch wide seats. Some of the rental companies have wheelchairs down to 16 inch wide, which is good for a small adult or school age child. The vendor list on the FAQs thread has information about places I know have smaller sized chairs.
If you tell the person making the reservation your child's height and weight, they can tell you if they have a size that should work.
One other possibility besides renting at WDW would be renting one from home and bringing it.
Advantages:
- you would be able to use it at the airport and would not need to arrange with the airline for skycap or wheelchair service.
- mobility devices fly for free - no extra fee and it does not count as baggage. You can gate check it and bring it right to the door of the plane. It will be at the door when you get off
- you would be able to use it all over, at the resort, at the parks, if you drive - from parking to the park
- often less expensive to rent from your home area than at WDW off site vendors
Disadvantages:
- you would have to transport it from your home to the airport and back again, which may be a tight fit.