How Does RA Affect Sagittal Alignment?
In order to better manage low back pain and spinal sagittal alignment in rheumatoid arthritis (RA) patients, researchers from Japan undertook a detailed study. Their work, “Factors influencing spinal sagittal balance, bone mineral density, and Oswestry Disability Index outcome measures in patients with rheumatoid arthritis,” was published in the February 2018 edition of the European Spine Journal.
Co-author Kazutaka Masamoto, M.D., with the Department of Orthopaedic Surgery Kyoto University in Japan, told OTW, “Our group tried to develop a safe strategy for the surgery for atlanto-axial subluxation and vertical subluxation in using Mergel’s transarticular screw. But after the advent of bio-DMARDs [disease-modifying anti-rheumatic drugs] and MTX [methotrexate], cervical deformities associated with RA have dramatically decreased. This problem requires cooperation between rheumatologists and spine surgeons.”
The authors wrote, “We enrolled 272 RA patients to identify the factors influencing sagittal vertical axis (SVA). Out of this, 220 had evaluation of bone mineral density (BMD) and vertebral deformity (VD) on the sagittal plane; 183 completed the ODI [Oswestry Disability Index] questionnaire. We collected data regarding RA-associated clinical parameters and standing lateral X-ray images via an ODI questionnaire from April to December 2012 at a single center. Patients with a history of spinal surgery or any missing clinical data were excluded.”
“Multivariate regression analysis showed that larger SVA correlated with older age, higher DAS28-ESR [disease activity score 28 erythrocyte sedimentation rate], MTX nonuse, and glucocorticoid use. Lower BMD was associated with female, older age, higher DAS28-ESR, and MTX nonuse. VD was associated with older age, longer disease duration, lower BMD, and glucocorticoid use. Worse ODI correlated with older age, larger PI-LL [pelvic incidence-lumbar lordosis] mismatch or larger SVA, higher DAS28-ESR, and glucocorticoid use.”
Dr. Masamoto commented to OTW, “In our country, RA is still an important field in orthopaedic surgery. And orthopaedic surgeons themselves take part in the control of RA. This study could be accomplished because of such backgrounds. We found that steroid intake has a bad influence on ODI, and MTX use has good effect on BMI. To improve low back pain in RA patients, a lot of aspects have to be taken into consideration.”
