Clinical features of Kashin-Beck disease in adults younger than 50 years of age during a low incidence period: severe elbow and knee lesions.

More than one million people are affected by Kashin-Beck disease (KBD) in a limited endemic area. However, few studies focused on the clinical features of adult KBD patients. The aim of this study was to investigate the clinical features of adult KBD patients who were younger than 50 years of age during a low incidence period. A special questionnaire was designed that surveyed general data, clinical symptoms, and signs and included the Visual Analogue Scale (VAS). Anthropometrics, the joint VAS, the range of joint motion (ROM), and joint function were measured. The VAS and joint dysfunction were compared among the different joints of extremities, and the relationship among the VAS, ROM, age, course of KBD, and number of enlarged knee and elbow joints elbow was analyzed. Two hundred forty-nine adult Tibetan KBD patients, matched with 249 healthy control subjects, have been surveyed. The VAS results show that the knee is the joint associated with the most pain, followed by the elbow. The elbow shows a higher percentage of limited ROM (47.0 %). The number of enlarged joints has a significant correlation with the VAS or elbow and knee ROM compared with the age or course of disease (P < 0.05). Severe elbow and knee lesions are important clinical features of KBD in adults younger than 50 years of age during a low incidence period. The number of enlarged joints can partially predict the VAS or ROM of elbow and knee and may be used for evaluating the patient's condition and function.