First 2yrs were goin as expected- Rough ! But now theres the thing about changing your anatomy ! And that it does, it transfers the loads to above and below the fixed site ! And thats why you should avoid pedical screw and rod system at all cost if possible in my personal opinion ! I have aquired a comp-frack at t-12 and hern-disk at l-5 since l-3-4 fusion 3yrs ago so back to the vicious disision making circle i go again ! Just a personal opinion Yall !