The most commonly affected disk space is L4-5
followed by L5-S1 and L3-4 [5]. The lumbar spine is
anatomically composed of 5 lumbar vertebrae that are
separated by the associated intervertebral disks. The cauda
equina travels within the vertebral canal, which is bordered
anteriorly by the posterior longitudinal ligaments that
function to stabilize the vertebral bodies and disks. The
localization of herniation to the lower lumbar disk makes
anatomic sense because of posterior thinning of the
longitudinal ligaments and the annulus fibrosis disk fibers
which leads to weakened disk spaces [6]. It then follows
that the weakened disk spaces help to promote herniation.
This mechanism is illustrated in