A case of Type I odontoid fracture in association with atlanto-occipital and atlantoaxial dislocation resulting in death is presented. The normal ligamentous anatomy is reviewed and proposed mechanisms for this injury are discussed. [ncbi.nlm.nih.gov]

• Asymptomatic

  Abstract A patient with Down's syndrome and asymptomatic atlanto-occipital instability is described. The relationship between atlanto-occipital instability, atlanto-axial instability and generalized ligamentous laxity, is discussed. [ncbi.nlm.nih.gov]

• Fracture

  It is proposed that the Type I odontoid fracture is a likely manifestation of atlanto-occipital instability and rarely occurs as an isolated or stable injury. [ncbi.nlm.nih.gov]

  Jefferson fracture: anterior and posterior C1 ring fracture, possible lateral masses displacement odontoid fracture: type 2 will cause posterior dens displacement and will disrupt Powers ratio atlanto-axial subluxation: atlantoaxial rotatory fixation [radiopaedia.org]

  Conclusion: To our knowledge, this is the first case of a simultaneous traumatic AOD and AAI without fracture in a neurologically intact patient. [pubmed.ncbi.nlm.nih.gov]

• Arthritis

  […] dens displacement and will disrupt Powers ratio atlanto-axial subluxation: atlantoaxial rotatory fixation will cause C1 lateral mass asymmetry relative to the dens Down syndrome: atlanto-occipital instability due to laxity of alar ligament rheumatoid arthritis [radiopaedia.org]

• Atlanto-Axial Instability

  The relationship between atlanto-occipital instability, atlanto-axial instability and generalized ligamentous laxity, is discussed. [ncbi.nlm.nih.gov]

The pathophysiology, diagnosis and surgical treatment are described. [ncbi.nlm.nih.gov]

Intraarticular atlantooccipital fusion for the treatment of traumatic occipitocervical dislocation in a child: a new technique for selective stabilization with nine years follow-up. Jeszenszky D, Fekete TF, Lattig F, Bognár L. Jeszenszky D, et al. [pubmed.ncbi.nlm.nih.gov]

The pathophysiology, diagnosis and surgical treatment are described. [ncbi.nlm.nih.gov]