I am 68 years of age.  Had extensive fusion to the lumbar spine in 2007.  The pain is still severe.  Especially the low back (numb) and the right knee and mid calf.  I also get shooting pains down the back of both legs.  Minimal ankle response and some knee response for refles.
Dear patient I would like to know why fusion was done? Fusion at some spinal level leads to loss of movements at that level due to fusion. To compensate for that movement increase at non fused spine levels and which leads to degeneration and spinal instability at higher level. Degenerative disease at higher level leads to back pain and nerve compression with numbness in both legs. Decreased ankle and knee response might be due to previous disease or recent nerve compression. Kindly get yourself investigated for MRI of lumbosacral spine to rule out nerve compression. All the best.