title: The anterior atlantodental ligament: its anatomy and potential functional significance.
abstract: OBJECTIVE
  Knowledge of the anatomy of the ligaments that unite the head to the neck is important to the clinician who treats patients with lesions in this region. Although the anatomy and function of the majority of these ligaments have been well described, some are relatively unknown. One of these includes the anterior atlantodental ligament (AADL). Our goal was to increase knowledge about the AADL.
  
  
  METHODS
  We dissected the craniocervical junction in sixteen adult cadavers and paid special attention to the presence and anatomy of the AADL.
  
  
  RESULTS
  The AADL was found in 81.3% of specimens. The attachment of each ligament was consistent and traveled between the base of the anterior dens to the posterior aspect of the anterior arch of the atlas in the midline and just inferior to the fovea dentis. In 38.5% of specimens, there was some connection between the AADL and the anterior atlanto-occipital membrane. The ligament was roughly 4 × 4 × 4 mm in all specimens. With transection of the transverse ligament, the AADL could be made taut with posterior distraction of the dens. In addition, with left and right rotation of the atlantoaxial joint, the AADL became taut (less than 10°) before any tautness of the alar ligaments in all specimens.
  
  
  CONCLUSIONS
  The AADL appears to resist posterior displacement of the dens and, with the alar ligaments, resists rotation. When present, the AADL contributes to the predental space. Knowledge of this ligament may aid in further understanding craniocervical stability and help in differentiating normal anatomy from pathology via imaging modalities.
authors: Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama, USA.
authors: R Shane
authors: RS
authors: Tubbs
authors: Martin M
authors: MM
authors: Mortazavi
authors: Robert G
authors: RG
authors: Louis
authors: Marios
authors: M
authors: Loukas
authors: Mohammadali M
authors: MM
authors: Shoja
authors: Joshua J
authors: JJ
authors: Chern
authors: Brion
authors: B
authors: Benninger
authors: Aaron A
authors: AA
authors: Cohen-Gadol
mesh_terms: D000368:Aged; D001268:Atlanto-Axial Joint / Q000033:anatomy & histology*; D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology; D002102:Cadaver; D001270:Cervical Atlas / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology; D008023:Ligaments, Articular / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000033:anatomy & histology; D016059:Range of Motion, Articular; D012727:Sex Characteristics