Trade encourages specialisation, which brings prosperity; global capital markets, for all their problems, allocate money more efficiently than local ones; economic co-operation encourages confidence and enhances security. Yet despite its obvious benefits, the globalised economy is under threat.
RA (the most common disease cause) and Paget disease of the cervical spine can cause atlantoaxial dislocation or subluxation, basilar invagination, or platybasia. Metastatic tumors that affect bone can cause atlantoaxial dislocation or subluxation.
In cases of rheumatoid arthritis, MRI is indicated when a neurologic deficit (myelopathy) occurs or when plain radiographs show (1) atlantoaxial subluxation with a posterior ADI less than or equal to 14 mm, (2) any degree of atlantoaxial impaction, or (3) subaxial stenosis with a canal diameter less than or equal to 14 mm.