Risk factors associated with cervical spine lesions in patients with rheumatoid arthritis: an observational study

BACKGROUND: Few reports have described the association between rheumatoid arthritis (RA) cervical lesions and osteoporosis, especially in patients with vertical subluxation (VS) that could be induced by the collapse of lateral masses in the upper cervical spine. Therefore, this study aimed to investigate the prevalence and risk factors for cervical lesions in patients with RA under current pharmacological treatments with biological agents, and to investigate the relationship between osteoporosis and VS development. METHODS: One hundred eighty-five consecutive patients with RA who underwent both cervical plain radiography and bone mineral density (BMD) scanning were enrolled. RA cervical lesions included atlantoaxial subluxation (AAS), VS, and subaxial subluxation (SAS). We assigned patients with AAS, VS, or SAS to the cervical-lesion group, and all other patients to the non-cervical-lesion group. Radiological findings, BMD, and clinical data on RA were collected. We used multivariate logistic regression analyses to assess the risk factors for cervical lesions in patients with RA. RESULTS: The cervical-lesion and non-cervical-lesion groups included 106 and 79 patients, respectively. There were 79 patients with AAS, 31 with VS, and 41 with SAS. The cervical-lesion group had a younger age of RA onset, longer RA disease duration, higher RA stage, and lower femoral neck BMD than the non-cervical-lesion group. Multivariate analyses showed that the risk factors for RA cervical lesions were prednisolone usage, biological agent usage, and higher RA stage. Prednisolone usage and femoral neck BMD were the risk factors for VS. CONCLUSIONS: Cervical lesions were confirmed in 57 % of the patients. Prednisolone usage, biological agent usage, and higher RA stage were significant risk factors for cervical lesions in patients with RA. The general status of osteoporosis might contribute to the development of VS.