Background The lumbar lesion in rheumatoid arthritis (RA) have been paid less attention, but some previous studies demonstrated the high prevalence of lumbar spondylolisthesis and lumbar scoliosis [1]. The lumbar lesion accompanied with RA is often difficult to treat, and it is important to know the characteristics of lumbar lesion in RA patients. The purpose of this study is to clarify the features of lumbar scoliosis in RA patients compared with degenerative lumbar scoliosis in non-RA patients.

Objectives A total of 54 patients (44 women and 10 men, 69.3±5.4 years, Cobb angle: 14.6±5.9) with scoliosis (Cobb angle of >10°) who fulfilled the revised criteria of the American Rheumatism Association were included in this study. As control, age, sex, and Cobb angle matched 54 patients without RA were selected and also included.

Methods We evaluated superior/inferior end vertebra, apical vertebra and osteophyte formation at L2/3, L3/4 and L4/5 using Nathan's classification (1-4) on plain X-rays [2]. The level of superior/inferior end vertebra, apical vertebra, and the levels of curve more than 10 °, and degree of osteophyte formation were compared between two groups using Man Whitney U-test.

Results The level of apical vertebra was significantly upper in RA than non-RA group. The level of superior end vertebra was also significantly upper in RA group, but there was no significant difference in the level of inferior end vertebra between two groups. The levels of curve was more wide in RA groups (RA group: 4.9±1.1 levels, non RA group: 3.6±0.7 levels, P<0.01). The degree of osteophyte formation was significantly greater at L3/4 and L4/5 in non RA group (L3/4: RA group 1.6±0.7 non RA group 2.2±0.9 P<0.01, L4/5: RA group 1.8±0.8 non RA group 2.5±0.7 P<0.01).

Conclusions The present results showed the differences between lumbar scoliosis with RA and that without RA. These differences may indicate that the process or cause of scoliosis development in RA is different from that of degenerative scoliosis. Further, the less osteophyte formation may suggest that the lumbar scoliosis with RA is more likely to have instability, and these differences should be taken into consideration in the treatment of lumbar scoliosis with RA.

References

1. Kawaguchi Y, Matsuno H, Kanamori M, Ishihara H, Ohmori K, Kimura T. Radiologic findings of the lumbar spine in patients with rheumatoid arthritis, and a review of pathologic mechanisms. J Spinal Disord Tech2003 Feb;16(1):38-43.

2. Nathan, Hilel. Osteophytes of the vertebral column. An anatomical study of their development according to age, race, and sex with considerations as to their etiology and significance. J Bone Joint Surg Am.1962. p. 243-68.

Acknowledgements We are very grateful to Atsuko Kamiyama for their valuable cooperation in my experiments.

Disclosure of Interest : None declared

DOI 10.1136/annrheumdis-2014-eular.2459