Sensitivity of total knee replacement wear to variability in motion and load input: A parametric finite element analysis study

Abstract

Polyethylene wear remains a contributor to long term failure in total knee replacements (TKRs). Advances in materials have improved polyethylene wear rates, therefore further wear reductions require a better understanding of patient‐specific factors that lead to wear. Variability of gait within patients is considerable and could lead to significant variability in wear rates that cannot be predicted by standard testing methods. An in‐silico study was performed to investigate the influence of gait variability on TKR polyethylene wear. Nine characteristic peaks within the load and motion profiles used for TKR wear testing were varied 75% to 125% from baseline (ISO‐14243‐3:2014) to generate 310 unique waveforms. Wear was calculated for 1‐million cycles using a finite element TKR wear model. From the results, a surrogate model was developed using multiple linear regression, and used to predict how wear changes due to dispersion of motion and force peaks within a) ±5%, the maximum allowable input tolerance of ISO, and b) ±25%, more reflective of patient gait inter‐variability. The range of wear within the ±5% tolerance was 0.65 mm3/million cycles and was 3.24 mm3/million cycles within the ±25% variability more in line with the dispersion observed within patients. Although no one kinematic or kinetic peak dominated variability in TKR volumetric wear, variability within flexion/extension peaks were the largest contributor to wear rate variability. Interaction between the peaks of different waveforms was also important. This study, and future studies incorporating patient‐specific data, could help to explain the connection between patient‐specific gait factors and wear rates.

Influence of Psychological Distress in Patients with Hypoallergenic Total Knee Arthroplasty. Treatment Algorithm for Patients with Metal Allergy and Knee Osteoarthritis

“…It is not clear if a positive SPT represents a real MA. In fact, despite being quite sensitive, false negatives are present in MA tests [ 13 , 29 , 33 ]. Therefore, either cutaneous MA has no correlation with deep MA, either a positive SPT is not an adequate test to determine a deep MA.…”

“…Quality of life and function were evaluated by three questionnaires: Western Ontario and MacMaster (WOMAC) OA Index [ 2 , 9 , 16 , 19 , 20 , 21 ], health questionnaire Short-Form-12 (SF-12) [ 19 , 22 , 23 , 24 , 25 , 26 ], and Euro-QoL-5D L-VAS (EQ5D) [ 27 , 28 , 29 ].…”

Computational Lower Limb Simulator Boundary Conditions to Reproduce Measured TKA Loading in a Cohort of Telemetric Implant Patients

“…Telemetric implant and kinematic data for nine TKA patients were adopted from the Orthoload database [15]. This provided 6-DOF loads acting on the tibial tray, as well as knee flexion, pelvic rotation, patient weight and height, and implant orientation.…”

“…Unfortunately, it is still relatively common to include only a single loading condition per activity, or a single implant alignment, essentially representing a single average patient. To address these limitations, researchers have recently been developing population-based analyses, including the impact of variation in loading conditions on implant wear simulation [15], or incorporating intersubject anatomical variation in assessing implanted patellofemoral joint kinematics and contact mechanics [16].…”

A review of advances in tribology in 2020–2021

“…towards more realistic applications. The advantage of the computational modelling was shown in parametric analyses for the design parameters of the hip [667] and the loading/motion in the knee [668]. Further applications of the computational modelling were made to investigate the effect of different daily activities of the hip [669] and wear of the lateral and medial compartments in the knee [670].…”