Sacrum

The sacrum is made due to the fusion of five sacral vertebrae (S1–S5). This fusion of the S2–S5 vertebra is usually complete before the age of 25. In its turn, the fusion of S1–S2 is slower, so at the age of 35, the sacral fusion is completed for only about half of the population*.


  • * Ríos L, et al. Sacral fusion as an aid in age estimation. Forensic Science International, 2008, 180(2-3):111.e1-111.e7.

  • Icon of crossfade image Front view of sacrum with terminology comments
    Front view of sacrum
    The front view of the sacrum
    The list of terms: Basis ossis sacri – Base of sacrum
    Apex ossis sacri – Apex of sacrum
    Ala sacralis – Ala of sacrum
    Processus articularis superior – Superior articular process
    Facies pelvica – Pelvic surface
    Foramina sacralia anteriora (pelvica) – Anterior sacral foramina
    Promontorium – Promontory of sacrum
    Lineae transversae – Transverse lines

    Icon of crossfade image Back view of sacrum with latin terminology comments
    Back view of sacrum
    The back view of the sacrum.
    The list of terms: Basis ossis sacri – Base of sacrum
    Apex ossis sacri – Apex of sacrum
    Processus articularis superior – Superior articular process
    Crista sacralis mediana – Median sacral crest
    Crista sacralis intermedia – Intermediate sacral crest
    Crista sacralis lateralis – Lateral sacral crest
    Foramina sacralia posteriora – Posterior sacral foramina
    Pars lateralis ossis sacri – Lateral part of mass of sacrum
    Tuberositas sacralis – Sacral tuberosity
    Facies auricularis – Auricular surface
    Hiatus sacralis – Sacral hiatus
    Cornu sacrale – Sacral horn

    Icon of crossfade image Side view of the sacrum with terminology comments
    Side view of the sacrum
    The lateral view of the sacrum.
    The list of terms: Basis ossis sacri – Base of sacrum
    Apex ossis sacri – Apex of sacrum
    Ala sacralis – Ala of sacrum
    Processus articularis superior – Superior articular process
    Facies pelvica ossis sacri – Pelvic surface
    Foramina sacralia anteriora (pelvica) – Anterior sacral foramina
    Promontorium – Promontory of sacrum
    Lineae transversae – Transverse lines
    Facies dorsalis ossis sacri – Dorsal surface of sacrum
    Tuberositas sacralis – Sacral tuberosity
    Facies auricularis – Auricular surface
    Cornu sacrale – Sacral horn

    Icon of crossfade image Top view of sacrum with terminology comments
    Top view of sacrum
    The top view of the sacrum.
    Note that intervertebral foramina observable through the sacral canal connect to both—ventral (pelvic) and dorsal sacral surface.
    The list of terms: Ala sacralis – Ala of sacrum
    Processus articularis superior – Superior articular process
    Canalis sacralis – Sacral canal
    Foramina intervertebralia – Intervertebral foramina
    Promontorium – Promontory of sacrum
    Crista sacralis mediana – Median sacral crest
    Crista sacralis intermedia – Intermediate sacral crest

    The sacrum. 360° rotation.

    First published: Oct/2019
    Last update: 19/Nov/2020