the articulations joining the articular facets of the axis and condyles of the occiput with the syndesmoses of the atlanto-occipital membranes.
2. Pathology
In this region various types of malalignment may occur, including dislocation, subluxation and instability. Precipitating factors include trauma and nontraumatic conditions such as rheumatoid arthritis, Downs syndrome, infection, calcium pyrophosphate dihydrate crystal deposition disease and congenital skeletal anomalies. Injuries to the occipitoatlantoaxial segment are the most frequent type of cervical spine injury in children.
Among the types of abnormalities involving this joint in rheumatoid arthritis are atlantoaxial subluxation, atlanto-occipital dissociation, erosion and fracture of the odontoid process, and erosion, sclerosis and fusion of apophyseal joints.
Fractures of the axis and atlas also occur in the occipitoatlantoaxial region.
DR
