Background The relationship between mechanical stress and radiographic damage in rheumatoid arthritis (RA) has been detected in patients with hemiplegia¹⁾ or poliomyelitis²⁾. In patients without neurological disorder, Koh reported that radiographic damage was worse and progressed faster in the dominant hand in individuals with early RA³⁾. However, few studies have detected the radiographic damage in the whole upper extremity on the mechanical stress.

Objectives To examine the relationship between mechanical stress and radiographic damage in RA, we evaluated the joint destruction of the dominant and non-dominant upper extremity.

Methods The joint destruction of the upper extremity (shoulder, elbow, wrist, metacarpo-phalangeal, interphalangeal, proximal interphalangeal) in 295 patients with RA, who were from 25 years to 91 years (mean age 64 years, mean disease duration 183 months, 86% females and 97% right-handed), was assessed according to the eroded joint, which was defined as ≥2 by Larsen scores for radiographic damage. These were divided into the dominant and non-dominant upper extremity. The Wilcoxon signed-rank test was used to examine the difference between the eroded joint count (EJC) in the dominant and the non-dominant upper extremity.

Results The mean EJC in the dominant and the non-dominant upper extremity was 2.4 and 2.05 respectively. The EJC was significantly more in the dominant than the non-dominant upper extremity. And, in regards to every joint of upper extremity, the eroded joint rate was higher in the dominant than the non-dominant

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Conclusions The eroded joint count of the upper extremity was significantly more in the dominant than the non-dominant one, therefore it was suggested that the mechanical stress influenced the radiographic damage in patients with RA

References

1. John H Bland, et al.: Hemiplegia and rheumatoid hemiarthritis. Arthritis Rheum (11) 1: 72–80, 1968.

2. E N Glick, et al.: Asymmetrical rheumatoid arthritis after poliomyelitis. Br Med J 3: 26–28, 1967.

3. Jung Hee Koh, et al.: Radiographic structural damage is worse in the dominant than the non-dominant hand in individuals with early rheumatoid arthritis. PLOS ONE, doi: 10. 1371/journal. Phone.0135409 August 6, 2015.

References

Disclosure of Interest None declared