atlantoaxial subluxation

atlantoaxial subluxation

Orthopedics An upper cervical spine subluxation which is either rotatory or anterior; rotatory AAS is more common in children, often due to apparently trivial injury; torticollis may be seen Imaging On an open mouth film, the odontoid is not equidistant between lateral masses of C1 Management Reduce subluxation and brace; recurrent or chronic cases can be treated with C1-C2 fusion; anterior AAS is due to traumatic disruption of transverse ligament Imaging Abnormal atlanto-dental interval; if anterior AAS is suspected, a CT rules out fracture; an MRI is used to evaluate the transverse ligament which, if disrupted, requires fusion; a cervical brace suffices for fracture without disruption. See Atlantodental interval.

atlantoaxial

pertaining to the atlas and axis.

atlantoaxial joint
the articulation between the first two cervical vertebrae.
atlantoaxial membrane
the fibrous sheet which closes the interarcual space between the atlas and the axis.
atlantoaxial subluxation
degeneration or malformation of the dens is seen mainly in toy breeds of dogs predisposing to displacement of the axis. Fracture of the dens can occur in any animal. Compression of the cervical cord is a common sequel that causes neck pain and varying degrees of spastic tetraparesis. Treatment is surgical stabilization. Also reported in Holstein cattle.
References in periodicals archive ?
In another rare situation, fusion of the lower cervical spine in DISH is possibly associated with enhanced mechanical stress at the craniocervical region, which could lead to soft tissue mass, odontoid fracture, atlantoaxial subluxation, and pseudotumor and then cause severe spinal cord lesion.
1,2] Anterior atlantoaxial subluxation and atlantoaxial impaction are the most characteristic cervical spine disease in RA, occurring in 13-70% and 4-35% of patients, respectively, worldwide.
Dewar, "Rotary fixation of the atlantoaxial joint: rotational atlantoaxial subluxation," Radiology, vol.
Anterior atlantoaxial subluxation is characterized by a radiographic distance of more than 3 mm between the anterior aspect of the dens and the posterior aspect of the anterior arch of the atlas.
Intermittent atlantoaxial subluxation caused by a prolapsing neurofibroma.
There was odontoid hypoplasia (one of the most critical feature of Morquio syndrome) along with atlantoaxial subluxation in radiographs of the cervical spine performed in flexion and extension views (Figs 1C and 1D).
Atlantoaxial subluxation is defined as an instability of the atlas (C1) over the axis (C2), due to failure or rupture of the ligament complex in the C1-C2 joint.
10), (11) However, little is known about the occurrence of falls, fall risk, and FOF in RA and, to our knowledge, there is no study which has evaluated the relationship between atlantoaxial subluxation (AAS) and FOF in conjunction with fall risk in patients with RA.
4,5) Craniocervical complications arise in 30% to 50% of patients who have had RA more than 7 years, while atlantoaxial subluxation with myelopathy develops in 2.
Intubation could be potentially hazardous due to a risk of atlantoaxial subluxation caused by cervical ligamentous laxity.
10,11,24) It should be taken into consideration that the bursa in the atlantoaxial joint, after being inflamed, may lead to atlantoaxial subluxation.