Facet Hypertrophy at L4-5 and L5-S1with resulting bilateral neural foraminal stenosis at L5-S1 left greater than right.[/QUOTE]
L - lumbar spine area and S - sacral area. It is a hypertrophy of spinal facet joints, usually due to normal ageing process. The hypertrophy can cause back pain for some persons and decrease the flexibility of the spine. The foraminal stenosis means that there is a pressure on a nerve passing from spine In a broader sense it means a disk degeneration: protrusion-bulg, disk flattening. If the MRI was done, perhaps you had any radiculopathy or sciatica symptoms

Good luck.
Adomas