This condition is know as spondylolisthesis. There reasons for this can be broadly categorized as congenital, devlopmental, degererative , traumatic and neoplastic.
This is a common condition seen after spondylolyis which is a defect in posterior part of the vertebra that displaces forward.
Old age may also lead to similar problems due to degeneration (wear and tear ) of the facet joints.
People with this problem generally do not have any problems - most of them will have pain on extension of the spine.
if associated with stenosis due to anterior slippage they may develop symptoms due to lumbar canal stenosis.
Spondylolisthesis is the slipping of one vertebra from its proper place over the one below it.
spondylolisthesis
Spondylolisthesis is the medical term for a vertebra that slips out of place. This condition is different from a "slipped disk."
herniated disk
The medical term for the region around a vertebra is "paravertebral." This refers to the area adjacent to the spine and includes muscles, nerves, and other structures close to the vertebral column.
Spondylitis means inflammation of a vertebra.
Anterolisthesis is the medical term meaning forward vertebral subluxation. It is a sliding forward of one vertebra on another.
Spondylitis is the medical term meaning inflammation of the backbone.
spondylosis spondyl/o = vertebrae/vertebra osis= abnormal condition
"Lumbar" refers to the region of the back or spine made up of the lumbar vertebrae. The 1st lumbar vertebra is just under the 12th thoracic vertebra. The easiest way to find this is to find the first vertebral body not connected to a rib. This is L1 (1st lumbar vertebra). There are 5 lumbar vertebrae (L1 through L5). The 5th lumbar vertebra sits on top of the sacrum (where your spine connects with your pelvis).
Laminectomy.Um if i had to guess itd be removing the outer bony section of the spine.?
Intervertebral
There are several different terms that could mean surgical repair of the spine, depending on which particular part of the spine was being repaired. Some examples include spinal fusion, disk replacement, discectomy, and many more.
spondylolisthesis
I believe the term you are looking for is the keel.
Vertebrate or verenickederatoror the term for animals that have a backbone.