Background Bone erosion is a common boney pathological finding of synovial joint in patients with rheumatoid arthritis (RA). The endplate of the lumbar vertebral body can also become eroded.1However, little is known about lumbar endplate erosion in patients with RA.
Objectives This cross-sectional study aimed to determine risk factors and the prevalence of lumbar endplate erosion evaluated by MRI in patients with RA.
Methods Lumbar and cervical plain radiographs and MR images were acquired from 201 patientswith RA who had never had spinal surgery. Lumbar endplate erosion was defined as irregularities of the intervertebral endplate or changes towards low intensity signals on MRI sagittal T1-weighted images. Erosion was graded as 0 (none) – 3 (severe) depending on the eroded area at each lumbar intervertebral disc. The scores from L1-2 to L5-S were then summed.Intervertebral disc degeneration was evaluated by Pfirmmann score and defined as the sum of the Pfirmmann scores from L1-2 to L5-S. Risk factors for lumbar endplate erosion were analyzed univariate and multiple linear regression analysis using age, sex, duration of RA, Steinbrocker RA stage, m-HAQ, DAS28-ESR, administration of steroids or biological products, cervical involvement of RA lesions, thoracolumbar vertebral fracture, lumbar spondylolisthesis, lumbar scoliosis and disc degeneration as variables. Low back pain was evaluated using a visual analog score and associations with lumbar endplate erosion were investigated.
Results lumbar involvement was Intervertebral lumbar endplate erosions were evident on MRI from 142 patients. On the plain radiograph, the incidence of vertebral fracture was 16%, that of spondylolisthesis was 26%, and that of scoliosis was 34%. The severity of the 191 (19%), 73 (7%), and 76 (8%) lesions was graded as 1, 2 and 3, respectively. Themean sum of the grade of lumbar endplate erosion was 2.81±3.22. Once bivariate analyses identified the significant variables. Age, sex, duration of RA, RA stage, m-HAQ, DAS28-ESR, cervical involvement of RA, vertebrae fracture, spondylolisthesis, scoliosis, and disc degeneration were determined with multiple linear regression. Multiple linear regression analysis showed that RAstage, vertebrae fracture, spondylolisthesis and disc degeneration were associated with increased lumbar endplate erosion scores (R2=0.28, p<0.05). Low back pain was not associated with lumbar endplate erosion.
Conclusions Lumbar endplate erosion in patients RA was associated not only with RA activity but also with lumbar degenerative changes. The incidence of lumbar involvement was relatively high. Lumbar endplate erosion by RA might accelerate lumbar degeneration.
Kawaguchi Y, Matsuno H, Kanamori M, et al. Radiologic findings of the lumbar spine in patients with rheumatoid arthritis, and a review of pathologic mechanisms. J Spinal Disord Tech 2003;16:38-43.
Disclosure of Interest K. Yamada: None Declared, A. Suzuki: None Declared, H. Yasuda: None Declared, S. Takahashi: None Declared, M. Tada: None Declared, Y. Sugioka: None Declared, T. Okano: None Declared, A. Kamiyama: None Declared, T. Koike Grant/Research support from: Takeda Pharmaceutical,Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbott Japan, Teijin Pharma, BanyuPharmaceutical and Ono Pharmaceutical, H. Nakamura Grant/Research support from: Chugai Pharmaceutical, Astellas, Speakers Bureau: Ono