A Study on Atypical Kashin-Beck Disease---an Endemic Ankle Arthritis

Background : To study the epidemiological characteristics of atypical Kashin-Beck disease cases without characteristic hand lesions such as interphalangeal joint enlargement and brachydactyly and the characteristics of ankle joint lesions. Methods : According to monitoring data, 4 types of regions (including none, mild, moderate and high Kashin-Beck disease endemic areas) in Heilong jiang and Jilin provinces were selected. All local residents over 40 years old were undergone clinical examanation and X-ray images of hands and feet.Kashin-Beck disease was diagnosed in accordance with the "Kashin-Beck disease diagnosis" standard (WS / T 207–2010) for the diagnosis of Kashin-Beck disease. Osteoarthritis was diagnosed in accordance with the American College of Rheumatology 1995 diagnostic criteria. Results : 119 residents over 40 years old were surveyed in a natural village in the non-endemic area. 1,190 residents over 40 years old were surveyed in 38 endemic KBD areas.A total of 710 patients with Kashin-Beck Disease were detected, including 245 patients with grade I, 175 patients with grade II, 25 patients with grade III, and 265 atypical patients. Among all investigated patients , 92.0% (653/710) had ankle joint changes, and it was 80.0% (196/245) in grade I patients and 95.4% (167/175) in grade Ⅱ. Varying degrees of ankle joint changes were found in both grade III and atypical patients. The grade of Kashin-Beck disease was correlated with the degree of ankle joint change ( P <0.001), and the correlation coefficient r s =0.376. Atypical Kashin-Beck disease patients in mild and severe endemic area of Kashin-Beck Disease were younger than those with typical Kashin-Beck disease. Conclusions : There is a correlation between the degree of ankle joint change and the grade of Kashin-Beck disease. The higher the grade of Kashin-Beck disease, the more serious the change of the ankle joint.