NATURAL COURSE OF CERVICAL-SPINE LESIONS IN RHEUMATOID-ARTHRITIS

Study Design. This study analyzed the natural course of cervical spine involvement in rheumatoid arthritis by serial radiographs. Objectives . The purpose waste determine the pattern of progression of cervical s pine lesions in rheumatoid arthritis:and predictors for the extent of progression. Summary of Background Data. Subluxation frequently occurs as a result of rheumatoid involvement of the cervical spine. It may b e severe in patients with mutilans deformities in the hands and feet. The extent of progression in a given patient is still unpredictable, M ethods, Serial cervical radiographs in 49 patients with rheumatoid art hritis were analyzed. The extent of progression was evaluated by rheum atoid arthritis subset defined previously, which reflected the final e xtent of joint erosion in this systemic disease and could be roughly c lassified during early stages of the disease. Results. In the upper ce rvical spine, reducible anterior atlantoaxial subluxation occurred fir st. Vertical subluxation of the axis appeared next. Irreducible change of preceding anterior atlantoaxial subluxation was a sign of the star t of vertical subluxation; In subaxial lesion, subluxation occurred le ss frequently (22.4%) than upper cervical lesion (77.6%). the extent o f progression was different-with the rheumatoid arthritis subset. In t he upper cervical spine, none of the subset with least erosive:disease developed vertical subluxation, whereas 52% of the subset with more e rosive disease and 88% of the subset with mutilating disease advanced to vertical subluxation. The extent of progression was well correlated with the number of joints with erosion. Subaxial subluxation was ofte n seen and became irreducible In mutilating disease and more erosive d isease, but not in least erosive disease. Conclusions, A progressive p attern of the upper cervical subluxations was clarified. That is, uppe r cervical lesions progressed from reducible anterior atlantoaxial sub luxation to irreducible anterior atlantoaxial subluxation with vertica l subluxation. This extent of progression was different with the rheum atoid arthritis subset, which was also related to the development of s ubaxial subluxation. The most aggressive arthritis classification, a s ubset with mutilating disease, had the more severe subluxation in both upper and subaxial cervical spine.