Not a doctor, but I had a similar situation about 15 years ago. After buying my first house, I bought several tons of material and landscaped the entire back yard with dry creek beds, stone paths, etc. Despite "lifting with my legs," it turns out a computer guy who sits on his butt 9.5 hours a day can't suddenly do several days' worth of strenuous manual labor without consequences.
I started having all sorts of problems. Lower back pain, burning and tingling down my leg, little spikes of pain behind my knee. The stiffness and pain got so bad I could hardly get out of bed in the morning. Turns out I had inflammation around the sciatic nerve in one of my legs. I was only 35 years old, how could I have sciatica like some old granny?
The first thing I learned, is that every back problem is different. People will give you all sorts of advice. Some people swear by chiropractors, they did nothing for me. I tried a vibrating massage chair, Icy Hot strips, sleeping on the floor, doing this and that...and it if anything, it only made things worse. My first visit to the doctor didn't help, and it was only when I went back and saw a different doctor that things improved.
Prescribed a combination of Hydrocodone (pain), Carisoprodol (muscle relaxer), and Vioxx (inflammation, pain), I felt better within hours of my first dose. That was a short-term solution, though. What really made me feel better was walking, so I walked and walked. Sometimes four hours a day. Combined with targeted exercises, I improved strength in my core, and within a few months I was off the meds and totally fine. Haven't had an issue in 15 years.
Your wife's situation is not similar. But like I said, each problem is different. Keep trying different things, and stay on her doctors to not dismiss her concerns. It may be surgery is the only option. It may be that things will never improve. But I think those are extreme cases. Just don't let the doctors push you around. You have to be your own advocate, because they are not going to go out of their way to try different approaches.