I have what you seem to be describing, a bone growth stimulator. There are a couple of different types. Mine is the EBI SpinalPak II. It's a small pocket sized unit with two electrodes. The sticky pads of the electrodes go 4-6 inches apart on each side of the incision and interact electronically to stimulate bone growth. It is worn all the time except in the shower. The patient doesn't feel it at all. I was showing bone growth at 6 weeks post-op and was fused at 3 months, amazingly fast. Bone growth typically doesn't start showing up until 6 or more months. I would think the stimulator (along with much prayer) had an impact!
There is another type that is like two picture frames that you wear, one on the front and one on the back. It's worn for 3-4 hours a day. I don't know of any particular advantages of one type over the other. Depending on the person, one or the other may be more convenient.
If it helps, why not? Definitely worth it if your doctor will order it and your insurance covers it.
Hope this was helpful.