To investigate the prevalence of knee osteoarthritis (KOA) in active steel workers and its correlation with factors such as knee imaging, metabolic diseases, lifestyle, and occupational work habits, in order to provide a theoretical basis for the early prevention and treatment of occupational musculoskeletal diseases among industrial workers in China.

This study was a cross-sectional survey. Knee joint imaging examinations and basic physical examinations were conducted on the on-the-job employees of Qian’an Iron and Steel Company of Shougang Co., LTD. Knee joint force line data such as femoral-tibial angle (FTA), medial proximal tibial angle (MPTA), and posterior tibial plateau angle (PTSA) were measured. The information such as medical history, living habits, and occupational labor habits was collected in the form of questionnaires, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were calculated. KOA screening was carried out for the above-mentioned population based on signs present on imaging, the self-report questionnaire, and objective indicators. Logistic regression analysis and other statistics were conducted to analyze the relationship between the included variables and KOA.

A total of 1230 knees from 615 respondents were included in the survey. Respondents were predominantly male (534 cases, 86.83%) with a mean age of (41.36±6.93) years. There were 925 knees (75.20%) with radiographic evidence of KOA, and 480 respondents (78.05%, including 35 cases or 5.69% with evidence in one knee and 445 cases or 72.36% with evidence in both knees) had at least one knee with radiographic evidence of KOA. There were 46 cases (7.48%) with a self-reported diagnosis of KOA based on the questionnaire, and 65 cases (10.57%) with a diagnosis of KOA based on objective indicators. Statistical analysis of the included variables showed that age, diabetes, arrhythmia, hyperuricemia and/or gout, and bending at work were associated with radiographic signs of KOA. Age, years of employment, family history of osteoarthritis, diabetes, hyperlipidemia, coronary heart disease, sedentary work habits, and objective indicators were associated with the diagnosis of KOA, whereas years of employment, family history of osteoarthritis, diabetes, coronary heart disease, heavy physical activity, and long-distance walking/stair climbing/long standing time/sedentary work habits were associated with the self-reported diagnosis based on questionnaires of KOA. In terms of symptoms and function, the WOMAC score was significantly higher in those with radiographic signs of KOA or diagnosed with KOA. In terms of radiographic measurement indicators, there was no statistically significant difference in the measured angles between those with radiographic signs of KOA or those diagnosed with KOA based on self-report questionnaires, whereas the PTSA angle was significantly increased in those diagnosed with KOA based on objective indicators.

The prevalence of KOA among steelworkers and the proportion of those with radiographic evidence of KOA are both high. Age, years of employment, family history of osteoarthritis, some metabolic diseases, and some work habits may be risk factors for the development of KOA.