Background Few studies have compared rheumatoid arthritis (RA)-related disorders of the cervical and lumbar spine.
Objectives The objectives of this study were to examine the prevalence of and risk factors for cervical and lumbar spinal instability in patients with RA.
Methods From a total of 1,843 patients registered in the Akita Orthopedic Group on Rheumatoid Arthritis (AORA), 128 patients [111 women, 17 men; mean age, 66 (41–84) years; mean disease duration, 14 (1–63) years] who underwent a radiographic examination were enrolled in this study. In the cervical spine, we defined instability as one of the following characteristics: (1) atlantodental interval (ADI) >3 mm, (2) Ranawat value <13 mm on a neutral plain radiograph, or (3) anteroposterior translation >3 mm at the subaxial cervical spine on an anteroposterior bending plain radiograph. In the lumbar spine, instability was defined as anteroposterior translation >3 mm on a neutral plain radiograph.
At the time of radiographs evaluation, demographic characteristics, clinical variables, medical history and current medications were investigated.
The patients were classified into two groups: with both cervical and lumbar spinal instabilities and without. The independent risk factors for both cervical and lumbar spinal instabilities were then determined using multivariate logistic regression analysis.
Results Forty-three (33.6%) patients exhibited cervical spinal instability, and 47 (36.7%) patients exhibited lumbar spinal instability. Twenty-two patients (17.2%) exhibited both cervical and lumbar spinal instability. The presence of both cervical and lumbar spinal instability was significantly and independently associated with disease duration (OR: 1.06; 95% CI: 1.01–1.12).
Conclusions The prevalence of both cervical and lumbar spinal instability in patients with RA was 17.2%. Disease duration was independent risk factor for presence of both cervical and lumbar spinal instability in this study.
Disclosure of Interest None declared