RESUMO
Objective To study the mechanism and the nomenclature of the lumbar disk herniation associated with posterior bony edge separation of the vertebral body, based on its CT findings in transverse and sagittal planes. Methods 18 patients with lumbar disk herniation were evaluated with the CT scan and sagittal reconstruction. Results There were 19 lumbar herniated disks associated with separated posterior bony edge of the vertebral body which protruded into the spinal canal. There was bony defect filled with disk material. In the sagittal plane, the bony separation and the posterior edge of the vertebral body formed the “V” type defect at 15 levels, and 4 were irregular or triangular. 15 cases of the disc herniation had bony separations and 4 had bone connection with the vertebral body. There were bony defect and sclerosis on the vertebral body edge. Conclusion The main mechanism was the separation compression of the herniated disk on the posterior vertebral body. The bony separation was the secondary change. So the authors suggest that such anatomical pathologic changes be named as intervertebral disk herniation associated with posterior bony separation of the lumbar vertebrae.