OBJECTIVES: To assess the association between occupational exposures and knee osteoarthritis (OA). METHODS: We systematically searched for observational studies that examined the relationship between occupational exposures and, knee OA and total knee replacement (TKR). Four databases were searched until Oct 1st , 2019. Two reviewers independently assessed study quality using the Newcastle-Ottawa Scale and evidence quality using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Subgroup meta-analyses were conducted for important study characteristics and each type of occupational exposure. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for meta-analysis using random-effects models. RESULTS: Eighty eligible studies were identified including 25 case-control (total study participants: N=20,505), 36 cross-sectional (N=139,463) and 19 cohort studies (N=16,824,492). Synthesis of 71 studies suggested increased odds of knee OA (OR: 1.52; 95%CI: 1.37, 1.69), which combined different physically demanding jobs and occupational activities, compared to sedentary occupations and/or low exposure groups. Odds of knee OA were greater in males, industry-based studies and studies assessing lifetime occupational exposures. There were 9 specific job titles that were associated with knee OA, including farmers, builders, metal workers and floor layers. Occupational lifting, kneeling, climbing, squatting and standing were all associated with a higher odds of knee OA compared to sedentary workers, respectively. CONCLUSIONS: Heavy physically demanding occupations and occupational activities were associated with increased odds of knee OA; as supported by moderate-quality evidence. Specifically, agricultural and construction sectors which typically involve heavy lifting, frequent climbing, prolonged kneeling, squatting and standing carried increased odds of knee OA.
Arthritis care res (hoboken)
Epidemiology, Knee Osteoarthritis, Meta-analysis, Occupation