Paul, I had mine cut in 2005 and in a 2008 MRI the crud buildup in the back was worse than it was before they operated the first time. No real pain after the surgery but it's now come back with avengence. The surgeon told me he cleaned things up as best he could but could not get everything. I won't be going for the next cut until both legs are numb instead of just one. Having neuropathy in the wrists and ankles does not help. I've asked for a new bottom, from the waist down and would even settle for a rebuilt one but no luck.