Subluxation of the atlantoaxial joint secondary to
inflammatory processes (pharyngitis and pharyngeal abscess) and head and
neck surgery. Major anesthetic implications (danger of quadriplegia,
especially during laryngoscopy and tracheal intubation; massive bacterial
pulmonary contamination if there is a rupture of a pharyngeal abscess).
Nontraumatic Atlanto-Axial Subluxation.
Although first described in 1830 by the Scottish physician
Charles Bell, it is named after the French otorhinolaryngologist P. Grisel who
described the features in 1930.
Rare. Literature suggests approximately 1:100,000,000
per year. Males and females are affected equally.
Usually affects children, but may be diagnosed late into adulthood.
Infection in the head and neck area spreads toward
the upper cervical vertebrae. The inflammation causes laxity of the
atlantoaxial ligament complex, leading to anterior subluxation of the atlas
on the axis. This probably follows rupture of the transverse ligament and
may result in spinal cord compression. The cause of infection may be (1)
postsurgery: mastoidectomy, tonsillectomy, adenoidectomy, removal of tumors, or
choanal atresia repair, (2) contiguous infection: rhinopharyngitis, tonsillitis, abscess
(retropharyngeal to alveolar), or ear infections, or (3) other more rare associations, such as acute
rheumatic fever or inflammatory bowel disease.
Usually clinical and it may be missed for months until
significant symptoms occur. Radiographs are of minimal value in the first 4
weeks, although flexion-extension views may be suggestive. CTand MRI scans
usually confirm the presence of rotational dislocation or anterior
subluxation. Flexible nasopharyngoscopy is useful.
Usually presents with progressive unrelenting
throat and neck pain followed by torticollis and subluxation. There is often
little systemic reaction. The torticollis is usually acute and often occurs
with sleep or minimal motion. Neurologic complications occur in
approximately 15% of cases and range from radiculopathy to myelopathy,
transient or permanent paraplegia, and even death. This can occur if the
atlas becomes dislocated and can occur following only minimal trauma. Treatment
includes antibiotics, surgical drainage of pus collections, bony
stabilization and neurologic protection.
In the acute phase of the disease, spinal protection often involves spinal traction treatment.
Chronic disease may require fixation, which is commonly
performed by an anterior approach.
Once the diagnosis is made, the
major concerns are spinal stability and the degree of neurologic compromise.
This is usually well established by clinical examination and scan results.
Assessment of the cause is important and may involve consideration of a
retropharyngeal or other upper airway abscess. Full assessment of the neck
is required because movement is usually severely restricted regardless of
Tracheal intubation may be extremely
difficult for several reasons: (1) unstable upper cervical spine with increased risk
for any movements, such as jaw support for face mask; (2) high risk of
complications if neurologic abnormalities are present; (3) causal abscess or
other airway inflammation/infection; (4) limited neck movement and mouth
opening because patient may be in traction; and (5) positioning is best ...