Cat hissing at tomcat after surgery?

Hello dear swarm intelligence,

I've browsed through the posts a lot, but unfortunately haven't found a solution to my problem.

About 6 weeks ago my tomcat broke his front leg. After surgery on his leg and another operation on his bladder three days later, he has been back home ever since. He had to stay in a cage for the first four weeks and has now had supervised outdoor access for a week. This means he is allowed out of the cage when I am there. My cat and tomcat have not been separated except for our appointments at the vet. The cage was in the living room and my cat always had access to it. Even then I noticed that she would hiss at him whenever she walked past the cage. The vet and various forum posts have recommended swapping their blankets so they get used to each other's smell, or that you simply have to wait until he no longer smells of the vet. If I put his blanket on her spot, she won't use that spot anymore. If I want to pet her after I've petted him, she flinches and hisses at me. If he's lying down somewhere, she will walk over and hiss at him. Lately, she's also been actively searching for him and giving him her claws. This isn't exactly ideal, and I have to say, I don't see any improvement; rather, it's getting worse. What else should I try?

The two were one and the same before the accident. I hope they can both get along again.

PS: Both are siblings from the same litter, almost 4 years old, are house cats, have three litter boxes, several water bowls, are fed wet food twice a day, and have dry food available to them. My tomcat had to change his food because of his bladder stones. But my cats won't eat it.

Best regards, Mine

The two before the accident