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. Trial registration PROSPERO (registration no. CRD42020196279).

Biomechanics of the medial meniscus in the osteoarthritic knee joint

Background Increased mechanical loading and pathological response of joint tissue to the abnormal mechanical stress can cause degradation of cartilage characteristic of knee osteoarthritis (OA). Despite osteoarthritis is risk factor for the development of meniscal lesions the mechanism of degenerative meniscal lesions is still unclear. Therefore, the aim of the study is to investigate the influence of medial compartment knee OA on the stress state and deformation of the medial meniscus. Methods The finite element method was used to simulate the stance phase of the gait cycle. An intact knee model was prepared based on magnetic resonance scans of the left knee joint of a healthy volunteer. Degenerative changes in the medial knee OA model were simulated by nonuniform reduction in articular cartilage thickness in specific areas and by a decrease in the material parameters of cartilage and menisci. Two additional models were created to separately evaluate the effect of alterations in articular cartilage geometry and material parameters of the soft tissues on the results. A nonlinear dynamic analysis was performed for standardized knee loads applied to the tibia bone. Results The maximum von Mises stress of 26.8 MPa was observed in the posterior part of the medial meniscus body in the OA model. The maximal hoop stress for the first peak of total force was 83% greater in the posterior horn and only 11% greater in the anterior horn of the medial meniscus in the OA model than in the intact model. The reduction in cartilage thickness caused an increase of 57% in medial translation of the medial meniscus body. A decrease in the compressive modulus of menisci resulted in a 2.5-fold greater reduction in the meniscal body width compared to the intact model. Conclusions Higher hoop stress levels on the inner edge of the posterior part of the medial meniscus in the OA model than in the intact model are associated with a greater medial translation of the meniscus body and a greater reduction in its width. The considerable increase in hoop stresses shows that medial knee OA may contribute to the initiation of meniscal radial tears.

Biomaterials and Meniscal Lesions: Current Concepts and Future Perspective

Menisci are crucial structures for knee homeostasis. After a meniscal lesion, the golden rule, now, is to save as much meniscus as possible; only the meniscus tissue that is identified as unrepairable should be excised, and meniscal sutures find more and more indications. Several different methods have been proposed to improve meniscal healing. They include very basic techniques, such as needling, abrasion, trephination and gluing, or more complex methods, such as synovial flaps, meniscal wrapping or the application of fibrin clots. Basic research of meniscal substitutes has also become very active in the last decades. The aim of this literature review is to analyze possible therapeutic and surgical options that go beyond traditional meniscal surgery: from scaffolds, which are made of different kind of polymers, such as natural, synthetic or hydrogel components, to new technologies, such as 3-D printing construct or hybrid biomaterials made of scaffolds and specific cells. These recent advances show that there is great interest in the development of new materials for meniscal reconstruction and that, with the development of new biomaterials, there will be the possibility of better management of meniscal injuries

Significant Increase in the Rate of Meniscal and Chondral Injuries Between Primary and Revision Anterior Cruciate Ligament Reconstruction. (188)

Objectives: Anterior cruciate ligament (ACL) injuries are often associated with meniscal and chondral lesions. Meniscal lesions are present in up to 50% of ACL injured knees, and chondral lesions occur with an incidence of 20% to 40% in acute ACL-injured knees. The major importance of this lies in the fact that menisectomy and severe chondral damage are important predictors of poor outcomes including the subsequent development of knee osteoarthritis. Furthermore, patient reported outcomes following revision ACL reconstruction remain inferior to primary ACL reconstruction and this may, at least in part, be due to an increased incidence and severity of meniscal and chondral injuries. Although multiple studies have demonstrated that meniscal and chondral lesions are generally present at a higher rate at the time of revision ACL reconstruction when compared to primary ACL reconstruction, large studies following individual patients through primary and revision ACL reconstruction and tracking the change in the occurence of these injuries are scarce. The primary objective of this study was to determine the proportion of patients with meniscal and chondral injuries at the time of primary ACL reconstruction and determine how this rate changed by the time they underwent revision ACL reconstruction. The hypothesis was that the proportion of patients with meniscal and/or chondral lesions would be significantly greater at revision ACL reconstruction when compared to the primary procedures. Methods: Consecutive patients who underwent primary and then revision ACL reconstruction between March 1999 and February 2018 were identified using a single center registry. Patient characteristics, and intraoperative data from each procedure were collected and analyzed. This specifically included the occurrence and type of meniscal and chondral pathology. Descriptive statistics were used to evaluate the study sample using medians, descriptive data analysis was conducted depending on the nature of the criteria. Comparison between variables were assessed with student’s t test for quantitative variables and Mcnemar test for categorical variables. Statistical significance was set a t p<0.05. Results: 213 consecutive patients underwent both primary ACL reconstruction and then revision surgery during the study period. The average time from primary ACLR to Revision was 46.8 ± 36.6 months (range 5-181).The mean age of patients at primary ACLR was 22.21±7.21 years. The mean age of patients at revision ACLR 26.1 ± 8.3 years. The mean IKDC for the entire population was 85.53 ± 11.59, The mean ACL-RSI score was 71.89 ± 23.95. The mean Lysholm score was 91.77±10.24. The proportion of patients with chondral lesions significantly increased from 7% at primary ACL to 15.5% at revision ACL (p < 0.05). Meniscal lesions also significantly increased from 44.6 % at primary ACLR to 70% at revision ACLR (p < 0.05). There was no significant difference in the rate of lateral meniscal lesions (11.7 vs 13.1, p > 0.05). However, the proportion of patients with a medial meniscus lesion (25.4 vs 36.2, p < 0.05) and bimeniscal lesions (7.5 vs 20.7, p < 0.05) increased significantly at revision ACL reconstruction. Conclusions: The proportion of patients with meniscal and//or chondral injuries at the time of revision ACL reconstruction is significantly higher than at the time of primary ACL reconstruction. Specifically, the rate of medial meniscus and bimeniscal injuries is significantly higher in patients undergoing revision ACL reconstruction

Magnetic Resonance Image Characterization of Knee Meniscus Signal Intensity using Crue’s Approach: Results from a Multi-centre Evidence

This study aimed to characterize knee meniscus signal-intensity using magnetic resonance imaging. Our research included knee MR images of 138 subjects from multi-centres in Nigeria, between September 2016 and December 2017. Knee images were retrieved from patients' folder of MRI scanners and transfered to a DICOM workstation (Onis 2.6) for image analysis. Knee meniscus was characterized into 0, 1, 2 & 3 grades using Crue’s grading approach. Our research revealed 58% incidence of meniscal lesion. Study yielded a significant relationship between meniscal lesion and gender (p <.005) with a greater proportion of these lesions in women than in men. Meniscal lesions showed significant association with osteoarthritis (OA) (p < 0.05). Grade 3 lesions (actual tears) were largely of horizontal configuration.

Relationship between abnormalities detected by magnetic resonance imaging and knee symptoms in early knee osteoarthritis

We investigated the prevalence of magnetic resonance imaging (MRI) findings and their relationship with knee symptoms in women without radiographic evidence of knee osteoarthritis (KOA). This cross-sectional cohort study included 359 Japanese women without radiographic evidence of KOA (Kellgren‒Lawrence grade < 2). All participants underwent T2-weighted fat-suppressed MRI of their knees. Structural abnormalities (cartilage damage, bone marrow lesions [BMLs], subchondral cysts, bone attrition, osteophytes, meniscal lesions, and synovitis) were scored according to the whole-organ MRI score method. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Score. Participants were divided into early and non-KOA groups based on early KOA classification criteria. Logistic regression analysis was performed to evaluate the relationship between MRI abnormalities and knee symptoms. Cartilage damage was the most common abnormality (43.5%). The prevalences of cartilage damage, BMLs, subchondral cysts, bone attrition, meniscal lesions, and synovitis were higher in patients with early KOA than in those without. Synovitis (odds ratio [OR] 2.254, P = 0.002) and meniscal lesions (OR 1.479, P = 0.031) were positively associated with the presence of early KOA. Synovitis was most strongly associated with knee pain and might be a therapeutic target in patients with early KOA.

The association of meniscal body height with knee structural changes in middle-aged and elderly patients with symptomatic knee osteoarthritis

Objectives: To investigate whether and how meniscal height is associated with osteoarthritis (OA)-related knee structural changes in symptomatic knee OA. Methods: We studied 106 patients (61 female, aged 40–73 years) with symptomatic knee OA. X-ray was used for Kellgren-Lawrence score. Meniscal body heights and extrusion were measured on coronal sections of intermediate-weighted MRI sequence. Knee structural changes were assessed using the modified whole-organ magnetic resonance imaging score (WORMS). Associations between meniscal body height and knee structural changes were assessed using linear regression analysis. Results: Higher medial meniscal body height was significantly associated with severe medial meniscal lesions (p = 0.001–0.023), medial compartmental cartilage lesions (p = 0.045), patellofemoral compartmental and medial compartmental bone marrow edema patterns (p = 0.001–0.037), anterior cruciate ligament and patellar ligament abnormalities (p = 0.020–0.023), and loose bodies (p = 0.017). However, lateral meniscal body height was negatively correlated with WORMS scores for lateral meniscal lesions (p ≤ 0.018), lateral compartmental cartilage lesions (p ≤ 0.011), and lateral compartmental bone marrow edema patterns (p = 0.038). Conclusion: Higher medial meniscal body height was associated with more severe medial compartment structural abnormalities and patellofemoral bone marrow edema patterns, while lateral meniscal body height was inversely correlated with the severity of lateral compartment structural abnormalities. Advances in knowledge: Our study revealed that meniscal body height was associated with multiple OA-related knee structural changes, which would be beneficial in identifying patients with or at risks for knee OA.