Mid-sagittal section view of the normal lower lumbar spine of a young female. The black arrows indicate normal disc height and anatomy. The following structures are labeled and easily identifiable: the nucleus pulposus (NP) of the L4-L5 disc, the large Batson's plexus of veins (BP), the cauda equina (CE), and the ligamentum flavum (LF).

Lateral sagittal section through the pedicles of the same specimen. The distinct texture of the lamella of the lateral portion of the annulus fibrosus (AF) can be seen. The L4 nerve root (NR) can bee seen as it exits beneath the L4 pedicle (P). The pristine cartilage of the facet joints (F) can be easily seen. The black arrow indicates normal lipping of the posterior inferior vertebral endplate.

Axial cross section at the mid-pedicle level of a normal lumbar vertebra. The coarse trabecular pattern of cancellous bone in the vertebral body (VB) can be readily identified. Note how the trabecular bone becomes more dense as it nears and enters the pedicles (P). Individual nerve roots can be seen suspended within the cauda equina (CE). The facet joints (F) are clearly visible and contain pristine cartilaginous surfaces. The vessels of Batson's plexus can be identified between the posterior vertebral body and the cauda equina.

Coronal section through a normal spine at the pedicles (P) of L2, L3, and L4. The L2-L4 nerve roots (NR) can be seen exiting the cauda equina (CE). Note how the dorsal root ganglia (G) are positioned beneath the pedicles at each level. Also note that the superior nerve roots run close to the lateral margins of the pedicles beneath. The black areas lateral to the cauda equina on both sides between L2 and L3 identify Batson's plexus.

Sagittal view cross-section of a degenerated L4-S1 vertebral segment. The L4-L5 disc (DD) bulges anteriorly beneath the ALL and posteriorly into the lateral recess, abutting the thickened ligamentum flavum (LF). The epidural veins are completely blocked. The L5-S1 disc is completely resorbed with total loss of disc height.

This sagittal section shows severe degenerative changes of the L4-5 motion segment. Note the almost complete resorption of the disc (D) with marked sclerosis (S) of the endplates and osteophyte (O) encroachment into the spinal canal. There is significant overriding of the articular surfaces with osteophyte (O) development on both the superior and inferior margins. There is infolding and redundancy of the ligamentum flavum (LF) further compromising space in the intervertebral foramen. The black area in the foramen is Batson's plexus of veins.

Sagittal cross section through the pedicles of a severely degenerated lower lumbar segment. The L5-S1 disc is almost completely degenerated, and there is marked sclerosis of both the inferior endplate of L5 and the superior endplate of S1. As a result of the loss of disc height, the L5 nerve root is being "guillotined" by the L5 pedicle above. There is marked overriding of the L5-S1 articular processes with a complete loss of surface cartilage. Compare this with the cartilage surfaces of the L4-L5 facet joint.

Axial view cross-section at the L4 vertebra reveals significant central and lateral recess stenosis. The white arrows indicate sclerosis and osteophyte development at the vertebral body. Osteophyte development (O) can also be seen on the superior articular processes. Note how the osteophytes bridge across and compromise the lateral recess space. The ligamentum flavum (LF) is redundant on both sides and severely limits the central canal.

Axial view cross-section at the L4-L5 disc level revealing severe degenerative spinal stenosis. The disc is compressing on the thecal sac anteriorly. The nerve roots of the cauda equina (CE) are severely compressed by the ligamentum flava (LF) posteriorly. Deterioration can also be seen at the facet joints (F).

Axial cross-section at the L5-S1 level. A foraminal herniation (H) of the L5-S1 disc has tracked upward behind the L5 body. The herniation displaces the L5 dorsal root ganglion (G) laterally and slightly superiorly and flattens the medial border of the ganglion.

Sagittal cross-section of a thoracolumbar compression fracture. The anterior compression of the vertebral body portion and retropulsion of a large triangular bone fragment (outlined) suggest a flexion-compression mechanism. The facet joints are bruised but not fractured.

Sagittal view of a Chance-like fracture/dislocation of the thoracolumbar spine. In this situation the injury has occurred through the T12-L1 disc space. There is associated complete disruption of the posterior ligaments. The T12 body is translated anteriorly over L1. Arrows indicate a hematoma in the conus medullaris.

Sagittal cross-section of a thoracolumbar spine showing osteoblastic tumor invading L1. This typically is associated with metastatic disease from the prostate gland. There are endplate irregularities with circumferential expansion of the vertebral body.

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