I have had 6 lumber surgeries since 1993 starting with a fusion at L4,L5 and S1, since then I have been fused all the way to L1. The 5 th surgery to fuse L2 and L1 the Dr. decided to use MBP rather than my own bone it the previous 4, it didn't take and 6 months later he had to refuse using a graft from my hip. The 8 to 9 months that followed were the best my back has felt since before the first injury 16 years ago. the last 3 months has felt like the L2 to L1 fusion is loose again and has been popping cracking and various pains in that area and lower portion of my body just like when the fusion didnt take after the time he used MBP. Has anyone heard of a fusion becoming loose 9mmonths later? is this possible? Are there any test to check the strength of a fusion? Also we found out after the last surgery that my bone that was used in the first surgeries is starting to grow across my spinal canal from one side to the other. Is this causing a problem with the overgrowth pushing on my spinal cord? This overgrowth is hard to see on a MRI and CAT scan and only was originally found during a Mylogram where the Dr. could not get through the bone to inject the dye. My Dr. didn't believe it until the last surgery. Does anyone have any suggestions or recomendations? thanks.