Objectives To examine the frequency of vertebral deformities in a population based cohort of female rheumatoid arthritis (RA) patients, and their relationship with bone mineral density (BMD) and demographic and clinical variables.

Methods Lateral radiographs of the spine were obtained from 229 female RA patients born 1926 or later (mean age (SD) 63.4 (6.7) yrs, mean disease duration 16.8 (10.4) yrs), recruited from a population based county RA register. Demographic and clinical variables were collected according to standardised procedures. Vertebral deformities were measured using a standardised semiquantitative method described by Genant, by an experienced radiologist (AH). Deformities were classified as mild, moderate or severe (a reduction in any of the vertebral heights of 20–25%, 25–40% and more than 40%, respectively). The patients underwent BMD measurements by DEXA of the femoral neck, total hip and lumbar spine (L2-L4) (Lunar Expert). T-scores were computed as provided from the manufacturer.

Results The total number of deformities was 168 (87 moderate or severe). Forty-nine (21.4%) of the patients had at least two mild deformities or one moderate/severe deformity. Mean BMD (SD) for femoral neck was 0,806 gm/cm² (0.152), total hip 0.836 gm/cm² (0.158) and L2-L4 1,053 gm/cm² (0,201). In bivariate analysis, vertebral deformities were associated with age, ESR, number of deformed joints, previous non-vertebral fracture, long-term corticosteroid use and with BMD at all three measurement sites (p < 0.05 for all variables). In logistic regression analysis, VD was independently associated with age, long-term corticosteroid use and with low bone mass at the hip.

Conclusion This study indicates that several factors are independently related to vertebral deformities in RA, and should be considered when trying to identify patients with this complication. Physicians should probably be especially aware of vertebral deformities in patients with a history of non-vertebral fractures and long-term corticosteroid use.