hi and welcome to the support group -
basically the info of 95% of failed fusions is quite high. Fusion surgeries have a high success rate in the range of 45% to 65%
and maybe a little higher.
I had a fusion (Anterior Lumbar Fusion L5-S1) done in 2/08. my surgery was a success as the surgeon did what he said he would do - remove the disc and put hardware in. I fused 100% but the surgeon told me he could not guarantee my pains would become better or that the nerves in my legs would get better.
Sometimes it can take up to a year or longer for nerve roots to heal and there are times when the damage is too great and they cannot heal. I had this happen to me - some surgeons will say that you have "FAILED BACK SURGERY SYNDROME" which is a phrase that is used way to loosely. It basically means that part of the surgery did not work as there is still pain. here's a site regarding it:
http://www.spine-health.com/treatment/back-surgery/failed-back-surgery-syndrome-fbss-what-it-and-how-avoid-pain-after-surgery I really don't see how surgeons can be sued because there is still pain and/or nerve damage. they can only hope that these will be part of the success of surgery. A fusion surgery is done to stabilize the spine and if the fusion takes and bone is growing back then it's a successful surgery.
I hope this helps - you can click on my name or pic and read my story - Joy