Occupational Physical Activity and Meniscal Tears: A Literature Review

Introduction

The menisci are two wedge-shaped disks of fibrocartilaginous tissue located in each tibiofemoral (TF) compartment. They are an important multifunctional component of the knee joint and play an essential role in load transmission, shock absorption, proprioception, and joint stability, and aids in joint lubrication and nutrition. The significance of the menisci to facilitate load distribution and reduce cartilage stress has been illustrated by an increased risk of subsequent degenerative changes in knees with earlier damage to or loss of the menisci. Meniscal tears are among the most frequent knee injuries. Factors that may lead to meniscal tearing include knee trauma, specific activities, degenerative changes, congenital changes, and instability secondary to previous ligament injuries. Tears are generally classified as traumatic or degenerative tears. Traumatic tears usually occur during pivoting knee traumas where the menisci are trapped in the TF compartment, whereas degenerative tears are associated with older age and knee osteoarthritis (OA). Epidemiological studies have shown that tears in the posterior horn of the medial meniscus are more prevalent than tears in the lateral meniscus. These observations might be explained by regional variations in material properties of the meniscal tissue, variations in meniscal mobility in different parts of the menisci, and a load imbalance between TF contact forces during ambulation. Forces across the knee joint are especially high during flexion and a significant stress concentration is located in the posterior part of the medial compartment in deep knee flexion. Occupation-related kneeling and squatting work could therefore be an example of an environmental impact that might be associated with an increased risk in the development of meniscal tears among workers with such work activities. The objective of the study was therefore to review the epidemiological literature and assess the evidence of a causal relationship between occupational physical activities and meniscal tears.

Abstract

The objective of this study was to conduct a systematic review of the literature examining the association between occupational physical demands and meniscal tears. A comprehensive literature search involving electronic databases (Medline, Embase, Cinahl, Web of Science, and Cochrane) was conducted along with the reference list of relevant publications. Peer-reviewed full-text articles published in English, German, or Scandinavian languages and concerning the incidence or prevalence of knee disorders, particularly meniscal pathology in different occupational trade groups, comprised the search criteria. Studies were assessed by their quality and the evidence of a causal relationship between occupational physical activity and meniscal tears evaluated using specific criteria for different levels of evidence. By merging results from the databases, a total number of 13 nonduplicate articles were found. The majority focused on occupational knee demands among workers in the construction and mining industry. Studies showed an increased prevalence of meniscal tears among workers with kneeling and squatting work tasks. The literature search revealed few relevant articles concerning the topic, and only three articles reached the level of high quality. It is concluded that evidence is still lacking of a causal relationship between occupational physical activities and meniscal tears.

Keywords

meniscal tears, occupation, knee, epidemiology