Definition
Common causes include :
- Down syndrome
- Rheumatoid Arthritis
- Trauma
- Ankylosing spondylitis
There are many potential causes of atlantoaxial instability. They are listed below with most common ones listed in bold:
- Rheumatoid Arthritis
- Achondroplasia
- Down Syndrome (occurs less frequently than atlantooccipital instability 10-20% vs 60%) (1)
- Grisel Syndrome
- Morquio Syndrome
- Congenital scoliosis
- Osteogenesis imperfecta
- Neurofibromatosis
- Larsen syndrome
- Spondyloepiphyseal dysplasia congenita
- Chondrodysplasia punctata
- Metatropic dysplasia (a rare syndrome that can present with AAI)
- Kniest syndrome (also can present with AAI; a workup must be performed prior to any operative interventions)
- Odontoid abnormalities
- Os odontoideum
- Ossiculum terminale
- Third condyle
- Hypoplasia or absence of the dens
- Pseudoachondroplasia
- Cartilage-hair hyperplasia
- Ankylosing spondylitis
- Scott syndrome
- Infections of the head and neck
- Tumors
- Trauma
- Cerebral palsy
- Steroid therapy
Keyword history
96%/2009
Sources
- Warner Jr, W. Pediatric Cervical Spine. Chapter 37. In: Canale & Beaty: Campbell’s Operative Orthopaedics. 11th edition. Mosby, 2007
- Banit D, Murrey D. Atlantoaxial instability. Webscape emedicine website. Accessed 2/27/15.