Transverse ligament of atlas

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Transverse ligament of the atlas
Membrana tectoria, transverse, and alar ligaments. (Transverse ligament visible at center.)
Details
Identifiers
Latinligamentum transversum atlantis
TA98A03.2.04.006
TA21703
FMA24961
Anatomical terminology]

In

dens (odontoid process) in contact with the atlas.[citation needed] It forms the transverse component of the cruciform ligament of atlas
.

Structure

The length of the ligament is variable; its mean length is 2 cm.[1]

The ligament broadens[1] and thickens[2] medially. The anterior medial aspect of the ligament is lined by a thin layer of articular cartilage.[1] The neck of the odontoid process is constricted where it is embraced posteriorly by the transverse ligament[2] so it retains the dens in position even after all other ligaments have been sectioned.[1]

Attachments

The ligament attaches on either side onto a small yet prominent tubercle upon the medial aspect of either lateral mass of atlas.[1]

Cruciate ligament

A strong median band (crus superius[2]) extends superiorly from the superior margin of the ligament to attach onto the basilar part of occipital bone (between the attachments of the apical ligament of dens, and tectorial membrane). A weaker and somewhat inconsistent median band (crus inferius[2]) extends inferiorly from the ligament to attach onto the posterior aspect of the[1] body of[2] axis. The ligament and the two median bands together constitute the cruciate ligament of atlas.[1]

Relations

The transverse ligament divides the vertebral foramen of the axis into an anterior portion (constituting one third of its lumen) which contains the dens, and a posterior portion (constituting two thirds of the foramen's lumen) which contains the spinal cord and its coverings[1] as well as the two accessory nerves (CN XI).[2]

Clinical significance

Excessive laxity of the posterior transverse ligament can lead to

atlantoaxial instability, a common complication in patients with Down's Syndrome. Laxity has also been hypothesized as the cause of degenerative hypertrophy and mechanical atlantoaxial stress.[3] Degenerative processes can give rise to transverse ligament cysts, resulting in progressive cervical myelopathy. The treatment of choice for transverse ligament cysts with progressive neurological decline is surgical resection and cervical fusion.[4] Conservative treatment with external neck immobilization is less commonly reported , but may be very useful in select cases where immediate surgical intervention is not indicated.[5][6]

See also

References

  1. ^
    OCLC 1201341621.{{cite book}}: CS1 maint: location missing publisher (link
    )
  2. ^
    Gray's anatomy
    , 1918
  3. PMID 22177924
    .
  4. PMID 21314283
    .
  5. PMID 16925084
    .
  6. PMID 29518219
    .
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