What Does MRI Scan Report-minimum Posterior Displacements L3 Upon L4 Indicate?

I have had an mri and the results are has follows minimum posterior displacements L3 upon L4 and of L4 upon L5. Mild faceto flavel hypertrophy noted at all levels. disc desiccation with loss of disc height and end plate changes noted at L3-L4. At L4-L5 There is further loss of disc height with end plate changes and posterior disc extrusion with minimum inferior migration impinging upon both the transiting L5 nerve roots in the lateral spaces and more marked on the left. the remaining spinal canal and intervertebrae foramina remain adequate calibre throughout and there is no evidence of neural compromise elsewhere in the lumber spine. the spinal cord terminates normally at the level T12-L1 and the conus returns normal signal c0onclusion lumber spondylotic changes with neurol compromise at L4-L5 AS described above. please help me to understand this. thanks june