L5 bi-lateral cortex breach from pedicle screws needs surgery?

8 yrs after an L5-S1 spinal fusion w/instrumentation my lumbar CT, post myelogram, showed a 3mm anyrtior breach into the lumbar cortex. Now, exactly 3 yrs later, the 3mm breach has become 11mm and now the rt. side has a 5mm breach after nothing 3 yrs ago. These are both L5 pedicle screws and, additionally, one of the cages has now moved, after 11 years, slightly laterally causing a slight narrowing of foraminal opening. The 11mm is on the left and now nrar the lumbar plexus. I recently developed a loss of ankle reflex and foot weakness on the same side(Left) as the 11mm breach as well. I am baffled by this high degree of change in the pedicle screws depth and with the cage novement I think something more than removal or replacement of the pedicle screws may be needed. I've been diabled from this fusion with severe low back pain (FBSS) and have a pain pump implanted to get some daily function. The newest myelogram supported the CT and I would appreciate any insight into what I may have in store for me later this summer. Thank You for your time and your opinions, I look forward to reading them.
Best Regards,
Mark