OP0245 Sites, Frequencies, and Causes of Fractures in Patients with Rheumatoid Arthritis: A Large Prospective Observational Cohort Study in Japan
Authors: K. Ochi, T. Furuya, E. Inoue, O. Ishida, K. Yano, Y. Sakuma, S. Yoshida, K. Ikari, A. Taniguchi, H. Yamanaka, S. Momohara
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Few studies have described in detail the fractures at all the skeletal sites in patients with rheumatoid arthritis (RA) <sup>1)</sup>. This information would be helpful for customizing strategies for preventing fractures in RA patients. <h3>Objectives</h3> The fractures occurring in Japanese RA patients were studied in detail by using the Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort study. <h3>Methods</h3> The IORRA is a prospective observational cohort study in Japanese RA patients at the Institute of Rheumatology, Tokyo Women's Medical University (Tokyo, Japan) and was started in 2000. A total of 9720 patients (82% women; mean age, 56 years) with RA were enrolled in the IORRA cohort study from 2000 to 2010. All participants self-reported whether or not they experienced a fracture event within the past 6 months; the site of the fracture (skull and face, chest bone, rib, pelvis, clavicle, shoulder, elbow, arm, wrist, hand, hip, leg, knee, ankle, heel, foot, or others [with comments]); and the causes of the fracture (accident, fall, spontaneous event, or sports injury). These patients were followed up every 6 months from October 2000 to October 2010. We then analysed the sites, frequencies, and causes of fractures to understand the epidemiology of fractures in Japanese RA patients. Statistical analysis were performed using Mann–Whitney's <i>U</i>-test and chi-square test, with a confidence interval of 95% (p = 0.05). <h3>Results</h3> During a mean duration of 5.2 years, 1357 patients (14%) reported a total of 2323 fractures. There were 563 (24.2%) clinical vertebral fractures and 1760 (75.8%) nonvertebral fractures (skull and face: n = 34 [1.5%]; chest bone: n = 9 [0.4%]; rib: n = 358 [15.4%]; pelvis: n = 71 [3.1%] clavicle: n = 56 [2.4%]; shoulder: n = 105 [4.5%]; elbow: 78 [3.4%]; arm: n = 86 [3.7%]; wrist: n = 121 [5.2%]; hand: n = 115 [5.0%]; hip: n = 177 [7.6%]; leg: n = 57 [2.5%]; knee: n = 83 [3.6%]; ankle: n = 129 [5.6%]; heel: n = 15 [0.6%]; foot: n = 266 [11.5%]) were reported. The frequencies of fractures at all the anatomical site differed according to gender; the most common fracture site in men was the rib, followed by the vertebra and hip, while that in women was the vertebra, followed by the rib, foot, and hip. Moreover, frequencies of rib, clavicle, and heel fractures were significantly high in men, while the frequency of shoulder fractures was significantly high in women. Spontaneous event was the main cause of clinical vertebral fractures (63.5%), while a fall was the main cause of both upper (76%) and lower (57%) extremity fractures. Rates of clinical vertebral and hip fractures increased, while those of rib and foot fractures decreased in older age groups. The rate of falls as the cause of nonvertebral fractures also increased in older age groups. <h3>Conclusions</h3> Our findings suggested that the causes of fractures may be differ according to the anatomical sites, and that prevention of fall would be most effective in reducing upper and lower extremity fractures especially in older RA patients. These differences should be considered while customizing strategies for preventing fractures in RA patients. <h3>References</h3> Kim SY et al. (2010) Risk of osteoporotic fracture in a large population-based cohort of patients with rheumatoid arthritis. Arthritis Res Ther 12:R154 <h3>Disclosure of Interest</h3> K. Ochi: None Declared, T. Furuya: None Declared, E. Inoue: None Declared, O. Ishida: None Declared, K. Yano: None Declared, Y. Sakuma: None Declared, S. Yoshida: None Declared, K. Ikari: None Declared, A. Taniguchi: None Declared, H. Yamanaka Speakers bureau: Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Wyeth K.K., Daiichi Sankyo Co., Ltd., Banyu Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Abbott Japan Co., Ltd., Eisai Co., Ltd., Santen Pharmaceutical Co., Ltd., Taishotoyama Pharmaceutical, Abbott, Eisai Co., Ltd., Takeda Pharmaceutical Company Limited, Mitsubishi Tanabe Pharma Corporation, Janssen Pharmaceutical K.K., Hoffmann-La Roche, Chugai Pharmaceutical Co., Ltd, Pfizer Inc., S. Momohara: None Declared