Occupational risk factors for meniscal lesions: a systematic review and meta-analysis

Background: Meniscal lesions are common and are associated with the development of knee osteoarthritis. Knee-straining activities at work such as kneeling or squatting cause high biomechanical stresses on the knee joints that can lead to acute or chronic injuries. The objective of this systematic review is to update the evidence on the potential relationship between occupational risk factors and meniscal lesions. Methods: We searched the Medline, Embase and Web of Science databases until August 2021 to identify epidemiological observational studies on the association between occupational risk factors and meniscal lesions. Study selection, data extraction and risk of bias assessment were performed independently by two reviewers. Effect measures were extracted from individual studies and pooled with random effects meta-analysis. Heterogeneity analyses were conducted. We used GRADE (Grades of Recommendations, Assessment, Development and Evaluation) to assess the overall quality of evidence. Results: The database search resulted in 11,006 references, and 46 additional studies were identified through hand search. Twenty-two studies (represented in 25 publications) met the predefined eligibility criteria and nine records were included in the meta-analysis. There was only one study with an overall low risk of bias. Significant associations between occupational risk factors and the development of meniscal lesions were found for kneeling (effect size (ES) 2.15, 95% CI 1.67-2.76), squatting (ES 2.01, 95% CI 1.34-3.03), climbing stairs (ES 2.28, 95% CI 1.58-3.30), lifting and carrying weights >= 10 kg (ES 1.63, 95% CI 1.35-1.96), lifting and carrying weights >= 25 kg (ES 1.56, 95% CI 1.08-2.24), playing football on a professional level (ES 5.22, 95% CI 3.24-8.41), working as a hard coal miner (ES 5.23, 95% CI 2.16-12.69) and floor layers (ES 1.99, 95% CI 1.43-2.78). The overall quality of evidence according GRADE was moderate to low. Conclusion: We found consistent evidence of an increased risk of meniscal lesions by occupational knee-straining exposures. Our findings are important for the development of preventive strategies to reduce work-related knee disorders and work absence.