RESUMO
Background: Lumbar backache is a very common problem nowadays. Sacralisation of lumbar vertebrae is one of the cause for that. During routine osteology teaching a sacrum with incomplete attached lumbar 5 vertebrae is seen. Observation: Incompletely fused L 5 vertebrae with sacrum is seen. The bodies of the vertebrae are fused but the transverse process of left side is completely fused with the ala of sacrum.But on the right side is incompletely fused. Conclusion: The person is usually asymptomatic or may present with symptoms which include spinal or radicular pain, disc degeneration, L4/L5 disc prolapse, lumbar scoliosis and lumbar extradural defects. In transitional lumbosacral segmentation, it was observed that the lumbosacral intervertebral disc is significantly narrowed. The incidence of disc herniation is found to be higher and can occur even at young ages. There was also relationship established between transitional vertebrae and the degree of slippage in spondylolytic spondylolisthesis. In addition, this anomaly has known implications in the field of disc surgery.