Dear Kim,
Welcome to the Disney Parks Moms Panel! I am so sorry to hear your husband had a rough time during his last visit!
My mom also has a severe bad knee problem and, let me tell you, I know exactly what you are talking about. We have been very lucky to (almost) always find a complimentary wheelchair at the bus stops that we can use to roll her over to the entrance except for a couple of times where she had to walk all the way to the entrance of Disney's
Animal Kingdom and then Disney's Hollywood Studios! She felt like her day was literally over right from the start! No rest or ice pack could help her recover those two days! We were told afterward that one of us should have contacted someone at security to go and get a wheelchair for her right after she got off the bus.
We were also advised to consider renting an ECV for the week from one of
Disney’s Featured Providers. This would allow your husband to move more independently around the park and resort without having to be pushed around. Also, when boarding buses, your party will be given preference and will board before others. The good thing is that these Disney Featured Providers will deliver your ECV directly to your Disney Resort if staying on property and will pick it up when you leave.
I hope these thoughts help with your vacation planning, Kim. If you have any more questions regarding your husband's needs or anything in general, please come back and see us again!
~Desiree