Upper thoracic myelopathy caused by vertebral collapse and subluxation in rheumatoid arthritis: report of two cases.

We report two cases of rheumatoid arthritis (RA) with upper thoracic myelopathy and a review of the literature. Clinical data of a 47-year-old woman (case 1) and a 54-year-old woman (case 2) are described. Case 1 showed a transverse-type myelopathy at the T2 segment level of the spinal cord and case 2 had the same type of myelopathy at the T4 segment level. Case 1 had anterior vertebral subluxation of C7 due to marked vertebral collapse and Case 2 had subluxation of T2 with vertebral destruction. These two patients had the mutilating type of RA with multilevel spontaneous fusion in the cervical spine. The lesions in the thoracic spine might be caused by the severe destructive inflammation that is characteristic in mutilating disease. The vertebral collapse might lead to subluxation of the upper thoracic vertebra, resulting in spinal cord compression. Upper thoracic subluxation might be caused by vertebral collapse due to RA and the increased motion as a compensation for decreased mobility caused by spontaneous fusion in the cervical spine.