First 3 to 4 weeks they were in this:
They disliked it but actually coped a lot better than I thought they would. To be fair it's bigger than a lot of hutches but they're used to having the whole room to themselves!
We then initially doubled that space using aviary panels, boxing them in to the corner of the room (although we had to put a sheet over them so Mj couldn't see the window edge - it's normally one of his favourite spots and the idiot kept trying to jump up onto them!).
We've since increased the space a bit more and it will be a bit longer before they have the whole room again but mainly because of the no jumping thing.
Lotty's been kept with him throughout - we felt terrible, that she was being 'punished', but it wasn't feasible to separate them.
The whole base on the big tray was covered in auboise so we didn't have to worry about a litter tray - only about keeping the cast dry. When we used the panels they had their normal litter tray back and he's been absolutely fine getting in and out
I mentioned this experience in another thread recently - being in confinement actually really helped us bond with Lotty (she's a tough cookie) and Mj loved lots of attention because they were so bored in confinement, we spent lots of one on one time with them which in a way was nice.
The antibiotics I believe was because the skin was broken, just a preventative measure but definitely no harm asking at the vets.
If it helps it was after 4ish weeks we really started seeing an improvement in Mj's leg. When the cast first came off he was holding the leg high off the ground, didn't rest on it etc then it settle down and he slowly used it again. He still doesn't have a full range of motion and it will probably be susceptible to arthritis in the future, it won't ever be the same but at least he has his leg!
I've added a picture of him in his cast so you can see it was tough for him but he is through it