BMP is only FDA approved last time I checked for Anterior (Approach through the front) spinal fusions. I broke my rod at age 22 after about 4 and a half years of having it implanted (pseudoarthrosis leading to rod breakage- aka hardware failure). My first fusion was done with an anterior approach from the mid thoracic to mid lumbar spine... a pretty big area to fuse to begin with- and 1 rod for this whole area through the right side of my rib cage (collapsing my lung, breaking out ribs and all that lovely stuff) using ribs for bone graft. My surgeon at the time, just like the one I have now was excellent but unfortunately I was young and dumb, which resulted in not following post op instructions leading to all these problems just a few years later. When my rod snapped, I felt a disgusting crack in my chest when i sneezed one day and it knocked the wind out of me- that's a pretty noticeable symptom. I figured I broken a rib, but after a month of severe side and back pain an x-ray showed a clear rod fracture resulting in a reinforcement surgery. The only reason the rod broke was because it failed to fuse the first time. The 2nd surgery to repair only the area where the rod snapped, was a big success thanks to a wonderful doctor and the desire to actually adhere to a post op plan. I'm getting another weak spot fixed this summer and I have full confidence in my surgeon. My main symptoms of problems involving my hardware was a crunchy sharp pain when I'd move most directions in the area of the weak spot and feeling achey pain as my ribs would spread in the said area (the 2nd being with the most recent weakness).
At < 1 year you probably will still have plenty of post op pain with activity or even lack of it. At a next appointment, looking into an xray or CT scan might not hurt if your physician feels it's necessary. I just hope you didn't make the same mistake I did and smoked cigarettes after your fusion. The continuation of my smoking was the prime reason for all the complications even now and failed fusion. If you have to go back in to surgery, make sure you're smoke free and a healthy fusion will be much easier to come by =)