L4 or Fourth Lumbar Vertebra, Lateral View

Description

Oriented in lateral profile, the L4 vertebra is presented with its large vertebral body anteriorly and the vertebral arch and spinous process projecting posteriorly. Short, thick pedicles bridge the body to the laminae, forming the lateral walls of the vertebral foramen, while the transverse process extends laterally from the pedicle lamina junction. Superior and inferior articular processes are visible as stacked facets posterior to the pedicle, defining the zygapophysial (facet) joint surfaces at the L3 to L4 and L4 to L5 levels. A small circled callout highlights a focal landmark on the posterior elements. L4 matters because it sits at the mechanical center of the lumbar lordosis and is a frequent reference point for both imaging and intervention, including level localization near the iliac crest line and needle trajectory planning for lumbar puncture or epidural placement. Facet orientation at this level, more sagittal than thoracic but transitioning toward the lumbosacral junction, helps explain patterns of degenerative spondylosis, facet arthropathy, and associated low back pain. Pedicle morphology is no abstraction, the stout L4 pedicle is a primary corridor for pedicle screw fixation, and its relationship to the spinal canal and exiting nerve roots drives safe hardware placement. Ideal for gross anatomy teaching on vertebral regional characteristics and for radiology correlation when comparing plain film obliques, CT bone windows, or sagittal reconstructions at the L4 level. Spine surgery texts and patient education materials can also use this lateral view to clarify posterior element anatomy, facet joint location, and common operative landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.