After 3 unsuccessful microdiscecomies I have been told that I must have a disc fusion of the S1. It also appears that I will require the same for the L4 down the track. Thankfully there is no sign of degeneration of the bone so I have asked about the option of disc replacement. This is apparently not an option for me with the S1 as too much bone from the vertebrae was removed to access and remove the offending burst disc matter from the nerve bundle area however, I am keen to know if it is possible to have disc replacement for the L4 before any surgery begins in this area. Has a combination of surgeries been done or is it possible? Info would be appreciated.