Lumbarization & sacralization

• Transitional vertebrae: 25% of normal cases.
• Sacralization of lumbar body: Spectrum from expanded transverse processes of L5 vertebra articulating with top of sacrum to incorporation of L5 vertebra into sacrum.
• Lumbarization of sacrum: Elevation of S1 vertebra above sacral fusion mass assuming lumbar body shape.
• Sacrum lies at 40° incline from horizontal at lumbosacral junction.
• Lumbarization & sacralization may appear similar that requires counting from C2 caudally to precisely define anatomy.

Lateral radiograph of sacrum & lumbosacral junction.