¡Hola Laura!
Welcome to planDisney! Oh no! I am so sorry to hear that your son has had an accident. I know that this can be extremely stressful, especially when planning a trip to the Most Magical Place on Earth! Many of the Walt Disney World attractions will be fine for your child to experience. The consideration will need to be the type of harness on the attraction, whether it requires the use of his arm to stabilize himself (i.e. in an attraction that is a roller coaster type), and whether the attraction involves water, because we all know water and a cast do not mix!
At Magic Kingdom, he should be fine for many attractions, such as
Peter Pan's Flight, Haunted Mansion, "it's a small world," and
Pirates of the Caribbean. If the attraction is a roller coaster, such as
Big Thunder Mountain Railroad,
Seven Dwarfs Mine Train, or Space Mountain, you will need to deduce whether he is ok with holding on with one hand. I would steer clear of Splash Mountain, as that does involve water.
At EPCOT, the new
Guardians of the Galaxy: Cosmic Rewind would definitely require the use of both hands to stabilize, so I would most likely avoid that one. The other attractions, such as Soarin' and
Frozen Ever After will be fine for him to enjoy. Within Disney's Hollywood Studios, it might be best for him to avoid the thrill attractions, such as
Rock 'n' Roller Coaster featuring Aerosmith. He would be fine on Twilight Zone Tower of Terror, and
Slinky Dog Dash, as well as
Millenium Falcon: Smuggler's Run, although I'd steer clear of the Pilot role, for now.
Finally, at Animal Kingdom, I do not recommend Kali River Rapids, as it involves water, and I would avoid
Expedition Everest - Legend of the Forbidden Mountain as it does involve a backward sequence, where both hands on the harness may be necessary. Also,
Avatar Flight of Passage, requires Guests to have both hands on their banshee, so that would probably be a no for now. Ultimately, it will depend on the recommendations of your physician, and how comfortable your son, and you, feel with him experiencing these attractions.
I hope for a speedy recovery and wish you a most amazing trip to Walt Disney World. Be sure to visit us at
planDisney en español for any future Disney vacation planning!
Malanie