Degenerative spondylolisthesis occurs due to degenerative arthritis of the disc and facet joints, which results in anterior displacement of a vertebra (usually L4 on L5).

• 退行性脊椎前移的发生是由于椎间盘和小关节发生退行性关节炎，从而导致椎体向前移位（通常是L4在L5上）。