Welcome to ATD. Thank you for the query.
The last transverse process (a bony protrusion near the L5 vertebra) is partially attached to the sacrum, or "sacralized". If this bony protrusion is attached to the sacrum, it can create a rudimentary joint (pseudoarticulation) where there shouldn't be one. The resulting motion in this section of the spine can sometimes be a cause of localized low back pain. This condition can usually be successfully treated without surgery. For instance, an injection of steroid medication at the pseudoarticulation of the transverse process and the sacrum can often be both diagnostic and therapeutic.
Hope this helps.All the best.
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