Biomechanical Evaluation of Isotropic and Shell-Core Composite Meniscal Implants for Total Meniscus Replacement: A Nonlinear Finite Element Study

Abstract

Loss of meniscal function due to symptomatic meniscal tears or meniscectomy leads to biomechanical instability and articular cartilage degeneration. Synthetic meniscal implants ought to ideally restore normal joint contact mechanics and thus forfending the overlying cartilage from degeneration. The purpose of this study was to quantify the contact stresses in both tibiofemoral compartments and joint kinematics during a gait cycle after implantation of a synthetic meniscal implant. Anatomically-detailed finite element model of the knee joint was developed from magnetic resonance images of a healthy female volunteer. Gait analysis was conducted using a three-dimensional motion capture system and computed the knee joint forces and moments and quadriceps muscle forces for a complete walking cycle. The effects of a synthetic meniscal implant on joint mechanics during gait were studied by conducting finite element simulations for the following meniscus conditions: (i) intact meniscus, (ii) meniscus with complete radial posterior root tear, (iii) total meniscectomy, (iv) isotropic meniscal implant, and (v) shell-core composite meniscal implant. Posterior root tear and total meniscectomy caused substantially increased contact stresses in both tibiofemoral compartments and altered tibial kinematics. Compared to posterior root tear and total meniscectomy, the isotropic and composite meniscal implants reduced the peak contact stresses in both compartments and reduced the cartilage nodes with higher contact stresses by disseminating the load over a large surface area. The shell-core composite meniscal implant resulted in lower contact stresses in the medial compartment relative to the other meniscus conditions. This study demonstrated that posterior root tear and total meniscectomy leads to detrimental changes in joint mechanics. Superseding the injured meniscus with a synthetic meniscal implant restored the joint mechanics close to the intact meniscal state. This novel synthetic meniscal implantation approach appears to be a promising strategy for treating patients with severe meniscal injuries.INDEX TERMS Biomechanics, finite element model, gait analysis, medical imaging, meniscal implant, musculoskeletal modeling.

Biomechanical assessment of disease outcome in surgical interventions for medial meniscal posterior root tears: a finite element analysis

“…We measured the peak stress of the medial/lateral compartments of the knee joint model as 7.9 MPa/6.3 MPa; given that the peak range of contact pressure of the medial/lateral compartment measured in biomechanical experiments on cadaveric specimens was 6-11 MPa/5-10.5 MPa [ 23 ], the contact stress of this model was within a reasonable range. In addition, in the numerical verification of the area, the total contact area of the medial/lateral intercompartment measured was 737.6 mm 2 / 550.6 mm 2 , which is consistent with a previous report [ 24 , 25 ] that found a total contact area of 650 ± 190 mm 2 /500 ± 90 mm 2 , respectively. The contact area of the medial compartment was higher than that of the lateral compartment.…”

Biomechanics of the medial meniscus in the osteoarthritic knee joint

“…Only stance phase of the gait cycle was simulated in the FE code Abaqus, because it has been well documented in-vivo ( Gilbert et al, 2014 ; Bergmann et al, 2014 ) and through modelling ( Shriram et al, 2019 ) that tibiofemoral contact forces and stresses are small during the swing phase compared to the stance phase. In the initial static step the equilibrium state between contacting surfaces was obtained for the imposed reference strains in the ligaments ( Table 3 ).…”

“…The finite element method (FEM) serves as a useful tool for investigating the mechanical status of the knee joint in different pathological conditions ( Kluess et al, 2009 ; Łuczkiewicz et al, 2016 ). Previous works ( Peña et al, 2005 ; Zielinska & Haut Donahue, 2006 ; Mononen, Jurvelin & Korhonen, 2013 ; Shriram et al, 2019 ; Zhang et al, 2019 ; Li et al, 2020 ) have focused on the influence of degenerative meniscal tears and meniscectomies on knee biomechanics. These FEM simulations were based on the geometry of healthy volunteers’ knee joints without changes typical of osteoarthritis.…”