OP: Contact Delta.
From their website:
https://www.delta.com/content/www/en_US/traveling-with-us/special-travel-needs/disabilities.html
QUOTE [bold added]
Disability Seating
We accommodate any request for seating that helps you manage your disability. It is our responsibility to provide you with any available seat, which you are qualified to use in the cabin of service purchased, in advance. Additional accommodation may be made for:
- Passengers who use an aisle chair to get on the aircraft — and can't readily transfer over a fixed aisle armrest — can be provided with a seat that has a moveable aisle armrest on some aircraft.
- Passengers traveling with an attendant helping them during the flight will be provided side-by-side seating
- Passengers traveling with a service or support animal will be accommodated with any available seat, but will be provided a bulkhead seat by request
- Passengers with a fused or immobilize leg will be provided with any available seat for which they qualify, on the side of the aircraft that appropriately accommodates their disability, or a bulkhead seat, by request
END QUOTE
From elsewhere on their website: "If you have specific questions that aren't answered here or you want to speak to someone about your special needs in person, call 800-221-1212"
SW