Is it something like this: https:/…
Personally I think it will be depending size and how you can proof the medical necessity.
Best is to contact the airline. Airports also offer services for people with reduced mobility. Maybe this is the solution?
Walking canes are allowed onboard but without knowing the size of yours and whether it folds down, its hard to say. Tell the airline specifically, its size and weight and see what they say. It may have to go in checked baggage and if that's the case, book passenger assistance to get you through airports and on/off the aircraft