Tribology studies of the natural knee using an animal model in a new whole joint natural knee simulator

Abstract

The successful development of early-stage cartilage and meniscus repair interventions in the knee requires biomechanical and biotribological understanding of the design of the therapeutic interventions and their tribological function in the natural joint. The aim of this study was to develop and validate a porcine knee model using a whole joint knee simulator for investigation of the tribological function and biomechanical properties of the natural knee, which could then be used to pre-clinically assess the tribological performance of cartilage and meniscal repair interventions prior to in vivo studies. The tribological performance of standard artificial bearings in terms of anterior-posterior (A/P) shear force was determined in a newly developed six degrees of freedom tribological joint simulator. The porcine knee model was then developed and the tribological properties in terms of shear force measurements were determined for the first time for three levels of biomechanical constraints including A/P constrained, spring force semi-constrained and A/P unconstrained conditions. The shear force measurements showed higher values under the A/P constrained condition (predominantly sliding motion) compared to the A/P unconstrained condition (predominantly rolling motion). This indicated that the shear force simulation model was able to differentiate between tribological behaviours when the femoral and tibial bearing was constrained to slide or/and roll. Therefore, this porcine knee model showed the potential capability to investigate the effect of knee structural, biomechanical and kinematic changes, as well as different cartilage substitution therapies on the tribological function of natural knee joints.

Tibiofemoral wear in standard and non-standard squat: implication for total knee arthroplasty

“…Therefore, the Authors who considered 0.3-0.4 slideroll ratio were correct with regard to beginning of the squat motion, but not with respect to the complete cycle. Above 30 degrees of flexion, as sliding prevails, wear starts developing between the surfaces due to the shear stress which is caused by the increasing slide 22 . Since the kinematic condition of the TKR geometries is different, wear must differ during the progression of the motion as well, which can be apparently observed on Figure 5.…”

“…One cycle in squat is defined between 0 to 120 degrees of flexion and extension while the complete range where the propagation of wear monitored is 15 years. A usual knee wear simulation period is 3.5 million cycles 22,23 however squat and deep squat is less frequently exercised in everyday life. If 3.5 million cycles were completed in 15 years, it would be 640 complete deep squat cycles carried out per day.…”

Development of a specimen-specific in vitro pre-clinical simulation model of the human cadaveric knee with appropriate soft tissue constraints

“…The proximal femur and distal tibia were cleaned of soft tissues to enable placement of the femur and tibia into cement pots (Fig 1). The knee was cemented using polymethylmethacrylate (PMMA; WHWPlastics, UK) and mounted to the knee simulator for investigation according to our previous study [6]. Throughout the procedure, the soft tissues were kept moist using Ringer's solution (Sigma-Aldrich, Buchs, Switzerland).…”

“…Throughout the procedure, the soft tissues were kept moist using Ringer's solution (Sigma-Aldrich, Buchs, Switzerland). The axial force axis was shifted medially by 0.07 of the tibial width by sliding the tibial pot in the fixture with the aim of causing greater medial compartment loading [6].…”

Evaluation of Biomaterials and Implant Production Process in Terms of Biotribology

“…Aiqin Liu ve ark [58]. tarafından "doğal diz için deneysel bir eklem simülasyon sistemi" geliştirilmiştir.…”