What does sacralized L5 with pseudo-articulation mean?

Sacralization lumbar. When one has sacralization of L5 vertebral body it becomes fused or a part of the sacrum. Such a condition shows only 4 lumbar vertebrae rather than the usual on x-ray imaging. If there is motion here at what should have been l4-l5 without the usual intervertebral disk, one could call this pseudo-articulation. In lumbaralization of the sacrum, there are 6 lumbar vertebrae on x-ray images.