When you state "major back surgery", I assume you had a fusion. If, yes, how many vertebral bodies did they fuse? Do you have a small incision on your hip? Curious if the surgeon used a bone cement called Nan-Oss. After I retired from Merck, I worked as a Clinical Research Coordinator for a six member ortho. group at the regional medical center. One of the device studies they were involved in followed a cohort of patients who were Nan-Oss recipients during their fusion surgeries. It was a really interesting combination compound, that, when mixed with a native bone plug was inserted at specific sites adjacent the vertebral bodies to be fused. The two-part formulation was nearly identical to native bone on the scanning electron micrographs we ran. Your osteoblasts "walk" down this "scaffolding", using it as a template to form new bone cells. Since it is a near match, structurally, for native bone when fully cured, the trial was designed to assess whether it would behave in similar fashion, withstanding vertical and torsional stress loading with similar longevity, in a near identical fashion to ulnar bone cells. It was formulated from hydroxyl-apatite crystals and single strands of collagen "teased" from their normal helical configuration via a proprietary technique. These single strand collagen fibrils behave very similarly to stem cells.
I saw some animal model data(dogs) where it was used to fill bone voids in compound fracture repairs-pretty impressive results!
First you have to heal all the layers of the muscle bundles the access surgeon cut through, then rebuild your lost muscle mass and strength. Don't overdue in an effort to speed the process early-on, your recovery will accelerate over time as the soft tissue injury heals. Outside of PT sessions, I started just walking up and down the beach in soft sand, slowly extending my distance,eventually shifting over to walking up and down sand dunes, initially with the aid of a pair of XC poles, and then ended without them for the last six weeks. It took me nearly eight months to recover to XC ski again, but I also had an initial surgery to restore the shattered vertebral body's height and configuration first, prior the fusion surgery.
Good luck, its a game of "fits and starts"! Just put your head down and keep reminding yourself that this is what if feels like to improve. As Steve and Al would probably echo, I will take back surgery over a knee arthroplasty anytime, having "sampled" them both.
