Atlantoaxial instability (AAI) is defined as excessive movement at the junction between the spine's first two vertebrae. It is unclear how common it is.

The surgical management of atlantoaxial instability remains one of the most challenging and delicate procedures in spinal surgery. Instability between the atlas (C1) and axis (C2) is often ...

Rachel Pighills, 33, of Worcester, has atlantoaxial instability, which is defined by excessive movement between the first and second vertebrae of her neck.

Haemmerli J; Ferdowssian K; Wessels L; Mertens R; Hecht N; Woitzik J; Schneider UC; Bayerl SH; Vajkoczy P; Czabanka M BACKGROUND CONTEXT: Due to the complexity of neurovascular structures in the ...

ORLANDO, Fla. — Type II odontoid fractures had a high rate of healing and a low risk of nonunion after treatment with posterior atlantoaxial screw-rod fixation, according to results of a study ...

In addition she has developed Atlantoaxial instability (AAI), making the top two vertebrae, which hold her skull in place, unstable and dislocated. Article continues below ...