title: The transverse occipital ligament: anatomy and potential functional significance.
abstract: BACKGROUND
  Knowledge of the anatomy of ligaments that bind the craniocervical junction is important for treating patients with lesions of this region. Although the anatomy and function of these ligaments have been well described, those of the transverse occipital ligament (TOL) have remained enigmatic.
  
  
  OBJECTIVE
  To describe the anatomy and functions of the transverse occipital ligament.
  
  
  METHODS
  Via a posterior approach, 9 cadaveric specimens underwent dissection of the craniocervical junction with special attention to the presence and anatomy of the TOL.
  
  
  RESULTS
  The TOL was identified in 77.8% of the specimens. The ligament was found to be rectangular with fibers running horizontally between the lateral aspects of the foramen magnum. The attachment of each ligament near the occipital condyle was consistent, and each ligament was found superior to the transverse portion of the cruciform ligament and inserted just posterior to the lateral attachment sites of the alar ligaments. The average width, length, and thickness of the TOL was 0.34, 1.94, and 0.13 cm, respectively. The TOL in some specimens also had connections to the alar and transverse ligaments.
  
  
  CONCLUSIONS
  The TOL was found in the majority of our specimens. The possible functions of this ligament when attached to the alar ligaments include providing additional support to these structures in stabilizing lateral bending, flexion, and axial rotation of the head. Knowledge of this ligament may aid in further understanding craniocervical stability and help in differentiating normal from pathology via imaging modalities.
authors.affiliation: Section of Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama 35233, USA. rstubbs@uab.edu
authors.forename: R Shane
authors.initials: RS
authors.lastname: Tubbs
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Griessenauer
authors.forename: Jenny Gober
authors.initials: JG
authors.lastname: McDaniel
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Burns
authors.forename: Anjali
authors.initials: A
authors.lastname: Kumbla
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Cohen-Gadol
mesh_terms: D000368:Aged; D001268:Atlanto-Axial Joint / Q000033:anatomy & histology* / Q000502:physiology; D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology* / Q000502:physiology; D001368:Axis, Cervical Vertebra / Q000033:anatomy & histology / Q000502:physiology; D002102:Cadaver; D001270:Cervical Atlas / Q000033:anatomy & histology / Q000502:physiology; D004210:Dissection / Q000379:methods; D005260:Female; D005539:Foramen Magnum / Q000033:anatomy & histology* / Q000502:physiology; D019416:Head Movements / Q000502:physiology; D006801:Humans; D008022:Ligaments / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009777:Occipital Bone / Q000033:anatomy & histology* / Q000502:physiology; D009809:Odontoid Process / Q000033:anatomy & histology / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology