After a hip fracture and surgery (plate and screws) is an upright walker/rollator ok to use for help getting around the house?

This is really a question that should be posed to someone familiar with the patient's fracture, surgery, healing rate, overall health, extent of arthritis and/or osteoporosis, leg strength, etc.   The operating surgeon would be one; a physical therapist would be another, and in some ways more accurate since he/she could observe the patient as he/she progresses.

That the patient has arthritis in his/her hands makes me think a walker shouldn't be used.   Too much pressure would be put on the arms and hands; if one hand should slip or become painful, using a walker single handed isn't an option and would be dangerous.

From experience, I think a rollator is safer and more sturdy.  If I'm ever in that position, I wouldn't even bother with a walker; I just don't think they're sturdy or safe enough.

This is something that should be evaluated by a Physical and or Occupational Therapist.
My Husband used a walker quite well after hip fracture repair. He was using it when he was in rehab after the repair.
Seek the advice from the PT and OT. have them evaluate the patient using the walker that you want them to use if it is different than one they might be using now. (there are a variety of walkers the upright ones do have the place where arms, and hands are placed are at a different height than a regular walker so using it to stand up from a seated position might be more difficult)

There is still hand use with one of the upright ones (we have one). Hands still needed to pull the person upright, and to use the brakes. Walking weight does rest on the forearms and shoulders while walking. Mostly we have found the upright walker helpful for back problems.