Biomechanical effects of medial meniscus radial tears on the knee joint during gait: A concurrent finite element musculoskeletal framework investigation

Abstract

The biomechanical variation in the knee during walking that accompanies medial meniscal radial tears stemming from knee osteoarthritis (OA) has not been explored. This study introduced a finite element musculoskeletal model using concurrent lower limb musculoskeletal dynamics and knee joint finite element analysis in a single framework and expanded the models to include knees with medial meniscal radial tears and total medial meniscectomy. The radial tears involved three locations: anterior horn, midbody, and posterior horn with grades of 33%, 50%, and 83% of the meniscus width. The shear and hoop stresses of the tear meniscus and tibial cartilage contact load, accompanying tears, and postmeniscectomy were evaluated during the stance phase of the gait cycle using the models. In the 83% width midbody tear group, shear stress at the end of the tear was significantly greater than in the intact meniscus and other tear groups, and the maximum shear stress was increased by 310% compared to the intact meniscus. A medial meniscus radial tear has a much smaller effect on the tibial cartilage load (even though in the 83% width tear, the cartilage/total load ratio increased by only 9%). However, the contact force on the tibial cartilage with total postmeniscectomy was increased by 178.93% compared with a healthy intact meniscus, and the peak contact pressure after meniscectomy increased from 11.94 to 12.45 MPa to 17.64 and 13.76 MPa, at the maximum weight acceptance and push-off, respectively. Our study shows that radial tears with larger medial meniscus widths are prone to high stress concentrations at the end of the tears, leading to the potential risk of complete meniscal rupture. Furthermore, although the tears did not change the cartilage load distribution, they disrupted the circumferential stress-transmitting function of the meniscus, thus greatly increasing the likelihood of the onset of knee OA. The significant increase in the tibial cartilage load with total postmeniscectomy indicates a potential risk of OA flare-ups. This study contributes to a better understanding of meniscal tear-induced OA biomechanical changes during human activities and offers some potential directions for surgical guidance of meniscectomies and the prophylaxis and treatment of OA.

Radial and longitudinal meniscus tears show different gapping patterns under stance phase conditions

“…However, the tears were simulated as a tissue loss, which was located next to the posterior root. In the region of our simulated radial tear, the in‐silico model of Wang et al, however, indicated shear stresses instead of compression in their circumferential tensor plot, thus, being in agreement with our findings 55 . While the inside‐out suture repair was able to successfully restore the outer and middle tear sections, the more critical inner, avascularised region 53 of the tear was not repaired and still tended to gap (Figure 10).…”

“…This appears to be a reasonable biomechanical behaviour, because the axial load, which is transferred via the convex-shaped surface of the medial femoral condyle, results in a splitting force which is normal to the meniscus surface. 54 A reverse behaviour was observed in the only study to quantify radial tears in in-silico by Wang et al 55 In their finite element model, radial tears were investigated at the medial posterior horn and compression forces were detected at the tear ends, causing the fragments to converge.…”

“…However, the tears were simulated as a tissue loss, which was located being in agreement with our findings. 55 While the inside-out suture repair was able to successfully restore the outer and middle tear sections, the more critical inner, avascularised region 53 of the tear was not repaired and still tended to gap (Figure 10). Furthermore, the inside-out suture migrated in the meniscus body during the sinusoidal preloading of the knee joints, which was quantified during a pre-test and resulted in a radial tear widening of 26% and a longitudinal tear widening of 2% under axial loading.…”

Model Properties and Clinical Application in the Finite Element Analysis of Knee Joint: A Review

“…12,123 Wang et al found that a radially wider incomplete tear of the medial meniscus could disrupt the circumferential stress transmission in the meniscus and that higher stresses at the end put the meniscus at risk of complete rupture. 124 It has been suggested that the maximum contact stress on the articular cartilage after meniscectomy was approximately twice that of a healthy joint, 125 with a significant increase in stress-strain on the lateral cartilage, 126 which might help to explain the cartilage damage and degeneration observed after meniscectomy. Meniscus replacement might delay long-term adverse events such as OA.…”

Effect of residual volume after surgery of the discoid lateral meniscus on tibiofemoral joint biomechanics: a finite element analysis

“…We set bone as a rigid material [18] and articular cartilage as an isotropic linear elastic material [19]. The materials of the anterior and posterior cruciate ligaments are set as Neo-Hookean hyperelastic materials, and other ligament materials are set as isotropic linear elastic materials [17,19]. The meniscus provided resistance against shear forces within the joint cavity and prevented outward expansion.…”