Hey I F,
I’m not sure I can help you, but it sounds like your medical history with your back and knee is almost identical to mine. I am 67 and had to retire four years ago from the remodeling business, due to back and knee surgeries. In 2002 I had surgery on my left knee, to repair a torn meniscus and remove some arthritis.
I had a back fusion (L 3-4) in 2006, after several years of spinal epidurals with steroids to manage the pain. I started taking Hydrocodone daily to help with the pain so I could keep working.
This DOES NOT help the source of the pain, but just blocks your brain from feeling it. So, like Greg said, it is not a long term solution.
Anyway, by 2011 I had to have my left knee replaced. The surgeon put it in “extra tight” because I told him I would be working for at least 10 more years, and he said he didn’t want it to wear out before I retired.
Well, it hurt ALL the time and last November had to be replaced again. By now my right knee was also past due and I had it replaced in March.

I’ve told you all this just to get to this: I believe all the knee (and back) problems have had a lot to do with additional back pain, plus the pain from sciatica. That’s the tingling pain you get down the outside of your leg. For those who may not know, this is caused by the sciatic nerve in the back, getting pinched as a result of inflammation around the spine.
One thing that can cause that is walking “goofy” ( not normal) because you’re trying to favor a leg or back to lessen the pain.

Here’s the good news!

During the course of my PT for my knee replacements with Brandi (some may remember the pic I posted; more than just a pretty face), I asked her if there was anything she could do to relieve the pain of sciatica. She said “sure!”. “A very simple exercise you can do anywhere.”
She had me do it right then, and within 3 minutes the pain was nearly gone! I’m going to try to describe it here; hopefully it will work for you as well as it has for me.

Stand next to a wall with your shoulder about 8-10” from wall and the leg with the sciatic pain farthest from the wall. Raise your forearm to about shoulder height, place it against wall in horizontal position, and lean your hips into wall. (see pic) Hold for 30 seconds. Return to straight standing position. Do 5-10 reps several times a day.
Be amazed!! Works for me....If anyone has any questions, PM me.

Got my knee replaced last year. It is what was hurting the most, so I started there. I was hoping that was the source of my back pain. I was wrong. It got to the point that I would avoid any walking, even a block or 2. Finally saw a specialist, and this was the diagnosis. I had lower back fusion done in 1984, and was told at the time that I may eventually have trouble above it. Doc wants an MRI before he does any treatment, but insurance won't pay for that until I get 6 weeks of physical therapy. Due to the average age on the stage (I'm probably about average or above, I'll be 65 in November) I thought maybe someone has had treatments or procedures that worked/ didn't work. I'm kind of bummed, hoping for a cortisone shot to get me through the harvest season but that would delay surgery if that is indicated by the MRI. I've been pretty depressed about my lack of mobility and thought I would reach out to the vast wealth of knowledge here.

Hey If, I had surgery for a ruptured disc (L4-L5) back in 2011, where they went in and cleaned out the fragments and therapy after that gave me some good exercises to stay loosened up and strengthen my core. I reinjured my back In 2015 and the MRI showed spinal stenosis on L3-L4 and L4-L5 which means that those discs are being compressed together which also leads to siatic nerve pinching where the nerve come on out of the spine and go into your legs thus causing pain and numbness clear into your feet. I was given 5 different exercises while lying on my back to stretch open those discs. It takes me about 25 minutes each morning to do the routine but it definitely helps me throughout the day. My chiro has a new machine for spinal decompression that a lot of people are using for relief of spinal stenosis also. You may want to look into that treatment also. Good luck and you have my prayers as I know what you are dealing with first hand, and it isn't fun. I turn 65 in November also. Hope you can get some permanent relief by the happy day.
MAS fish

Still hoping to hook up with you at the Amana's at some point. The son and DIL were there last Saturday.