This form of AAI, found predominantly in the hereditary connective tissue disorder populations, is due to alar ligament incompetence, as opposed to the transverse ligament failure in rheumatoid arthritis and Down syndrome. ĪAI Fielding type 1 subluxations are characterized by anterior displacement of the facet primarily on one side, with a normal atlanto-dental interval. This cohort is comprised primarily of Ehlers-Danlos syndrome, hypermobility type (designated as h-EDS), in whom the diagnosis of AAI requires dynamic imaging, such as rotational CT of C1-2 to show pathological angular displacement, or lateral neck tilting to demonstrate lateral displacement. While others have reported open reduction of fixed subluxation in children with neck deformity but no significant functional or neurological symptoms, this study addresses Fielding type 1 rotary subluxations (AAI) in patients with substantial functional and neurological symptoms, in the context of hereditable connective tissue disorders. The inflammatory connective tissue disorders are no exception: prior to the development of effective disease-modifying pharmacotherapies, 88% of rheumatoid arthritis patients exhibited radiographic evidence of C1-C2 involvement, 49% were symptomatic, 20% were myelopathic, and 10% succumbed to death. Healey reported on eight subjects with Goldenhar syndrome, of which three had AAI. One-third of children with ligamentous laxity due to congenital spondyloepiphyseal dysplasia suffered from AAI with cervical myelopathy. Of Halko’s 4 subjects with vascular EDS, three had AAI. Down syndrome has an 11 to 17% incidence of AAI. Therefore, AAI is not uncommon in conditions of lax ligaments. The atlanto-axial joint, the most mobile in the body, is stabilized primarily by ligaments. And developmental conditions, such as atlanto-occipital segmentation failure-the HOX-D3 homeotic transformation-are also recognized as predisposing to AAI. AAI can also occur with minimal or no trauma in children as a result of ligament laxity.

The last few decades have witnessed increased recognition of AAI in the connective tissue disorders, including inflammatory disorders (such as rheumatoid arthritis, systemic lupus erythematosus, Stihl disease, ankylosing spondylitis) and heritable disorders, such as Ehlers-Danlos (EDS), Stickler, Loeys-Dietz, Marfan, and Morquio syndromes (Mucopolysacharridosis IV) spondyloepiphyseal dysplasia and congenital hemifacial microsomia conditions, such as Goldenhar syndrome. Alignment and stabilization is associated with improvement of pain, syncopal and near-syncopal episodes, sensorimotor function, and exercise tolerance.Ītlanto-axial instability (AAI) results most commonly from trauma, due to injury of the transverse odontoid ligament, less commonly from congenital conditions such as os odontoideum or Klippel-Feil syndrome, and least commonly neoplasm or infection.

The diagnosis of Fielding type 1 AAI requires directed investigation with dynamic imaging.

Patients reported improvement in the frequency or severity of neck pain ( P < 0.001), numbness in the hands and lower extremities ( P = 0.001), headaches, pre-syncope, and lightheadedness (all P < 0.01), vertigo and arm weakness (both P = 0.01), and syncope, nausea, joint pain, and exercise tolerance (all P < 0.05). At 15 months, two subjects underwent reoperation following a fall (one) and occipito-atlantal instability (one). Subjects underwent a modified Goel-Harms posterior C1-C2 screw fixation and fusion without complication. Subjects diagnosed with a heritable connective tissue disorder, and AAI had failed non-operative treatment and presented with severe headache, neck pain, and characteristic neurological findings. This retrospective, IRB-approved study examines 20 subjects with Fielding type 1 rotary subluxation, characterized by anterior subluxation of the facet on one side, with a normal atlanto-dental interval. Atlanto-axial instability (AAI) is common in the connective tissue disorders, such as rheumatoid arthritis, and increasingly recognized in the heritable disorders of Stickler, Loeys-Dietz, Marfan, Morquio, and Ehlers-Danlos (EDS) syndromes, where it typically presents as a rotary subluxation due to incompetence of the alar ligament.

Cervical spine x ray down's syndrome