I understand that the penultimate vertebrae has been broken as vertebral disc cannot break but herniate or prolapse.

Der Bandscheibenvorfall (lateinisch Prolapsus nuclei pulposi, ärztlich oft Nucleus-pulposus-Prolaps (abgekürzt NPP)), auch Bandscheibenprolaps (BSP), Discushernie (oder Diskushernie) und Discusprolaps, ist eine Erkrankung der Wirbelsäule, bei der Teile der Bandscheibe in den Wirbelkanal – den Raum, in dem das Rückenmark liegt – vortreten.
https://de.wikipedia.org/wiki/Bandscheibenvorfall

At the bottom of the skull, there are 7 chained cervical vertebrae followed by 12 dorsal vertebrae. The spine ends with the 5 lumbar vertebrae (L1, L2, L3, L4, L5) and the sacrum. The latter is composed of 5 triangular vertebrae (S1, S2, S3, S4, S5).
https://en.lombafit.com/herniated-disc-and-paralysis-of-the-...

The majority of spinal disc herniations occur in the lumbar spine (95% at L4–L5 or L5–S1).[21] The second most common site is the cervical region (C5–C6, C6–C7).
https://en.wikipedia.org/wiki/Spinal_disc_herniation

While the discs in the lower (lumbar) region of the spine are most often affected in intervertebral disc disease, any part of the spine can have disc degeneration.
https://medlineplus.gov/genetics/condition/intervertebral-di...

Intervertebral disc, anulus fibrosus, annulus fibrosus, nucleus pulposus. Illustration from Anatomy & Physiology, Connexions Web site. http://cnx.org/content/col11496/1.6/, Jun 19, 2013.
https://www.ncbi.nlm.nih.gov/books/NBK470583/figure/article-...

There are thirty-three vertebrae in the human vertebral column—seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, five fused sacral vertebrae forming the sacrum and three to five coccygeal vertebrae, forming the coccyx.
https://en.wikipedia.org/wiki/Vertebra

The adjacent figure depicts the general characteristics of the first through fourth lumbar vertebrae. The fifth vertebra contains certain peculiarities, which are detailed below.
https://en.wikipedia.org/wiki/Lumbar_vertebrae

Otherwise: The diagnosis refers to the L3/L4 lumbar intervertebral disc for adults, or to the S3/S5 sacral intervertebral disc for children if the sacral has not yet been fused.

The following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical intervertebral spaces, the sacrum, and the coccyx.
:
Lumbar disc herniations occur in the back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum.
https://en.wikipedia.org/wiki/Spinal_disc_herniation

The L3-L4 spinal motion segment, positioned in the middle of the lumbar spine, plays an important role in supporting the weight of the torso and protecting the cauda equina (nerves that descend from the spinal cord). While the L3-L4 motion segment is less likely to be injured compared to its lower counterparts, it may be subject to degeneration, trauma, and disc-related problems.
https://www.spine-health.com/conditions/spine-anatomy/all-ab...

Before the operation : disc herniation at L2-3, L3-4, and L4-5.
https://www.researchgate.net/figure/Before-the-operation-dis...

To determine the timeline of sacrum formation in mice, the sacral discs (S1/S2, S2/S3, S3/S4) of male FVB mice at a range of ages from neonatal (postnatal day 4, P4), rapid growth phase (4 weeks), end of longitudinal growth period (12 to 14 weeks) to middle-age (1 year old), were compared by X-ray (Fig. 1B) and histomorphometric analysis of Hematoxylin and Eosin (H and E)-stained mid-coronal sections (Fig. 1A,C-F).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6078355/

A similar Gaussian distribution was noted for the level of the tip of the thecal sac (r=0.9639). Fig. 3 showcases the results, with a Gaussian distribution clearly visualised. The mean level of termination was 7.128 (95% CI (6.95, 7.31)), corresponding to mid-S2. The data ranged from the L5-S1 disc to the S3-S4 disc.
The data ranged from the L5-S1 disc to the level of lower S3 in males, and the L5-S1 disc to the S3-S4 disc in females.
https://www.springermedizin.de/assessment-of-the-levels-of-t...

Figure 3: Typical anatomy of the human lumbar intervertebral disc. The annulus fibrosis (AF) is composed of concentric layers similar to a fiber composite, while the nucleus pulposis is an isotropic gel capable of evenly distributing loads to the vertebral endplates and AF
https://www.researchgate.net/profile/John-Domann/publication...