I am a 51 year old female experiencing lower back pain for several years. I was finally able to get an MRI, and neuro discussed surgery. I just don't know what it all means and would appreciate help interpretating and understanding if the possibility of permanent damage exists. I understand the diagnoses of spondylolethesis, but what is everything else here? I am unable to sit or stand for very long, and my left leg to my foot frequently tingles. Following is the text:

MRI LUMBAR SPINE WITHOUT CONTRAST 7/8/10
Comparison is made to conventional films of the lumbar spine of 1/26/10 and 7/23/09

INDICATIONS 47 female with back pain. The conventional films of the lumbar spine demonstrated increasing anterior displacement of L5 on S1 as compared to the earlier study of 7/23/09.

FINDINGS
ALIGNMENT There is anterior displacement of L5 on S1 by 9mm
CONUS MEDULLARIS Normal
SOFT TISSUES There are incidental right renal cysts
VERTEBRAE There are no compression fractures. There are several foci of high signal intensity , primarily in the L3 and L4 compatible with incidental benign hemangiomata. There is irregularity of the endplates at T11-12, T12-L1 and L2-3 compatible with Schmori's nodes.

LUMBAR DISK LEVELS
L1-2 There is disk degeneration. There is no local disk protrusion.
L2-3 There is minimal disk degeration. There is bulging of the annulus.
L3-4 There is no significant abnormality.
L4-5 There is disk degeneration. There is bulging of the annulus. There is mild facet and ligamentum flavum hypertrophy, right greater than left.There is bilateral foraminal narrowing.
L5-S1 There is disk degeneration. There is bulginf of the annulus.There is prominent bilateral foraminal narrowing, left greater than right with impingement upon the L5 nerve roots, left greater than right. There is also central spinal stenosis. There may be mild impingement upon the right S1 nerve root in the spinal canal.
CONCLUSION Severe disk degeneration at L5-S1. Anterior displacement of L5 on S1. Prominent facet and ligamentum flavum hypertrophy with sever bilateral foraminal narrowing, left greater than right with impingement upon the L5 nerve roots, left greater than right. Probable impingement on the right S1 nerve root in the spinal canal.

Disk degeneration , bulging annulus and facet and ligamentum flavum hypertrophy at L4-5.