question: Hello, my husband is 35 years old- had spinal fusion in 2000 after a car accident. They fused at L4-L5. I am trying to read his newest MRI scan and it says L4-5 anterior spondylolisthesis , disc bulging and facet hypertrophy causing posterolateral subarachnoid impingement. Does the subarchnoid impingment mean it is going into his spine?