Total Knee Replacement Polyethylene Stresses During Loading in a Knee Simulator

2000 ◽  
Vol 123 (4) ◽  
pp. 842-847 ◽  
Author(s):  
Virginia L. Giddings ◽  
Steven M. Kurtz ◽  
Avram A. Edidin
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Tibial Component ◽  
Joint Kinematics ◽  
Knee Simulator ◽  
Flexion Extension ◽  
Total Knee ◽  
Von Mises ◽  
Anterior Posterior ◽  
Bumper System

We investigated the stresses and kinematics of a total knee replacement during the duty cycle of a knee simulator. Finite element models were constructed of the tibial and the femoral component of a commercially available cruciate retaining total knee replacement. Time dependent flexion/extension, axial loading, and anterior/posterior loading were applied to the components of the arthroplasty to match those generated by the knee simulator. We evaluated the effect of varying the stiffness of a spring-loaded bumper system for anterior-posterior constraint on the joint kinematics as well as on the stresses within the polyethylene tibial component. Both the joint kinematics and the stresses and strains subjected to the polyethylene tibial component, were found to be comparatively insensitive to the stiffness of the spring bumper system for this design. When the stiffness of the bumper system was increased by two orders of magnitude, the maximum contact stresses, von Mises stresses, and von Mises strains in the polyethylene tibial component varied by only 15 to 59 percent. In general, increasing the stiffness of the bumper system decreased the displacements of the base plate, but the relationships were nonlinear, possibly due to the added constraints imposed by the tibiofemoral contact interaction. The long-term goal of this research is to develop a validated structural model to predict the stresses, kinematics, and ultimately, the wear, of total joint replacement components in a contemporary knee joint simulator.

scholarly journals Comparison of the Kinematics Following Gait Perturbation in Individuals Who Did or Did Not Undergo Total Knee Replacement

2021 ◽  
Vol 11 (16) ◽  
pp. 7453
Author(s):  
Vicktoria Elkarif ◽  
Leonid Kandel ◽  
Debbie Rand ◽  
Isabella Schwartz ◽  
Alexander Greenberg ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Plantar Flexion ◽  
Joint Kinematics ◽  
Gait Velocity ◽  
Timed Up And Go ◽  
Flexion Extension ◽  
Risk Of Falls ◽  
Total Knee ◽  
One Year

We aimed to compare the spatiotemporal parameters and joint kinematics during unperturbed and perturbed gait between individuals with osteoarthritis (OA) who did or did not undergo total knee replacement (TKR) one year post a baseline evaluation. OA subjects scheduled for TKR (TKR group; n = 14) and not scheduled for TKR (NTKR group; n = 17) were age-matched. Outcome measures included: joint range of motion, timed up and go, joint pain levels, Oxford score, and the Activities-specific Balance Confidence Scale. In addition, spatiotemporal gait parameters and joint kinematics were recorded during perturbed and unperturbed gait. After one year, most of the TKR group (71%), but only 41% of the NTKR group, increased their gait velocity by more than 0.1m/sec, which is the meaningful clinical important difference for gait velocity. After perturbation of the contralateral limb, the TKR group showed a greater decrease in the maximal extension of the OA hip compared to the NTKR group (p = 0.031). After perturbation of the OA limb, more subjects decreased their OA knee flexion–extension range in the NTKR group compared to the TKR group (p = 0.011) and more subjects decreased their maximal ankle plantar flexion in the TKR group (p = 0.049). Although the surgery was successful in terms of pain reduction and increased functionality, individuals following TKR exhibited unique compensatory strategies in response to the perturbation of both limbs. These findings might suggest that balance deficits remain in individuals following TKR and therefore are associated with a risk of falls.

The dog as a preclinical model to evaluate interface morphology and micro-motion in cemented total knee replacement

2012 ◽  
Vol 25 (01) ◽  
pp. 01-10 ◽  
Author(s):  
M. A. Miller ◽  
M. Khorasani ◽  
K. L. Townsend ◽  
M. J. Allen ◽  
K. A. Mann
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Subchondral Bone ◽  
Tibial Component ◽  
Preclinical Model ◽  
Interface Morphology ◽  
Material Interfaces ◽  
Post Surgery ◽  
Total Knee ◽  
Micro Motion

SummaryObjectives: This study investigated cemented fixation of the tibial component from a canine total knee replacement preclinical model. The objective was to determine the local morphology at the material interfaces (implant, cement, bone) and the local relative micro-motion due to functional loading following in vivo service.Methods: Five skeletally mature research dogs underwent unilateral total knee replacement using a cemented implant system with a polyethylene (PE) monobloc tibial component. Use of the implanted limb was assessed by pressure-sensitive walkway analysis. At 60 weeks post-surgery, the animals were euthanatized and the tibia sectioned en bloc in the sagittal plane to create medial and lateral specimens. High resolution imaging was used to quantify the morphology under the tray and along the keel. Specimens were loaded to 50% body weight and micro-motions at the PE-cement and cement-bone interfaces were quantified.Results: There was significantly (p = 0.002) more cement-bone apposition and interdigitation along the central keel compared to the regions under the tray. Cavitary defects were associated with the perimeters of the implant (60 ± 25%). Interdigitation fraction was negatively correlated with cavitary defect fraction, cement crack fraction, and total micro-motion.Clinical significance: Achieving good inter-digitation of cement into subchondral bone beneath the tibial tray is associated with improved interface morphology and reduced micro-motion; features that could result in a reduced incidence of aseptic loosening. Multiple drill holes distributed over the cut tibial surface and adequate pressurization of the cement into the subchondral bone should improve fixation and reduce interface micro-motion and cavitary defects.

The Effects of Resection Technique on Implant Migration in Single Radius Posterior-Stabilized Total Knee Replacement

2018 ◽  
Vol 33 (01) ◽  
pp. 078-083
Author(s):  
Matthew G. Teeter ◽  
Kevin Perry ◽  
Xunhua Yuan ◽  
James L. Howard ◽  
Brent A. Lanting
Keyword(s):  
Total Knee Replacement ◽  
Femoral Component ◽  
Knee Replacement ◽  
Tibial Component ◽  
Posterior Stabilized ◽  
Gap Balancing ◽  
Measured Resection ◽  
Total Knee ◽  
Single Radius ◽  
Component Migration

AbstractThe purpose of the present study was to measure the effects of gap balancing and resection techniques on migration of a single total knee replacement implant design. A total of 23 patients (24 knees) were recruited on referral to either a surgeon performing gap balancing or a surgeon performing measured resection and followed prospectively. All patients received a fixed bearing, posterior stabilized total knee replacement implant of a single radius femoral component design with cement fixation, and all aspects of care outside of resection technique were identical. Patients underwent radiostereometric analysis (RSA) at 2 weeks (baseline), 6 weeks, 3 months, 6 months, 1 year, and 2 years. Migration of the tibial and femoral components was compared between groups. Tibial component migration was greater at 2 years in the gap balancing group (mean difference = 0.336 mm, p = 0.036), but there was no difference at 1 year. One measured resection and three gap balancing tibial components demonstrated continuous migration > 0.2 mm between years 1 and 2. There was no difference in femoral component migration. Small differences in tibial component migration were found between the gap balancing and measured resection techniques. However, comparing the migration to established predictive thresholds for long-term loosening risk, implants performed with both techniques were found to have equally low revision risk.

scholarly journals Prospective, observational study to evaluate the relation between patient-reported outcomes and component rotation in total knee replacement: protocol for the CRACK study

BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e031166
Author(s):  
Hans-Peter van Jonbergen ◽  
Ellie Landman ◽  
Maarten Horst ◽  
Robin Westerbeek ◽  
Ydo Kleinlugtenbelt
Keyword(s):  
Total Knee Replacement ◽  
Clinical Outcomes ◽  
Outcome Measures ◽  
Knee Replacement ◽  
Tibial Component ◽  
Patient Reported Outcomes ◽  
Persistent Pain ◽  
Component Rotation ◽  
Patient Reported ◽  
Total Knee

IntroductionTotal knee replacement (TKR) for osteoarthritis results in a satisfactory outcome in the majority of patients, although up to one in five patients may be dissatisfied with the outcome. Persistent pain is a main contributor to patient dissatisfaction, and femoral and tibial component malrotation have been identified as a potential cause for both persistent pain and patellofemoral problems. Based on the assumption that component malrotation is the causative factor for persistent pain, early revision for patients with symptomatic malrotated components has been advocated in the literature. However, convincing evidence that component malrotation indeed results in less than optimal outcomes is lacking. This study aims to assess the relation between knee prosthesis component rotation and patient-reported outcomes in a large group of patients and to determine the range of femoral, tibial and combined rotation that results in the best clinical outcomes.Methods and analysisIn this single-centre, prospective observational cohort study, a total of 500 patients will undergo TKR. All patients will have a 3D-CT assessment of femoral and tibial component rotation within 8 weeks after surgery. Outcome measures will include the Oxford Knee Score, the Knee Injury and Osteoarthritis Outcome Score, EQ-5D, visual analogue scale for pain, the American Knee Society Score and the knee joint range of motion. We will assess the relation between femoral, tibial and combined component rotation and patient-reported outcome measures at 8 weeks and 1 year of follow-up, and we will determine the range of femoral, tibial and combined rotation that results in the best clinical outcomes.Ethics and disseminationEthical approval for this study has been granted by the Isala Hospital ethics committee. The results will be published in a peer-reviewed journal and presented at relevant meetings.Trial registration numberNL7635.

A Performance Test to Assess Strategies to Transfer Weight During Knee Flexion and Extension With Rotation for Individuals With a Total Knee Replacement

2012 ◽  
Author(s):  
Lauren Ferris ◽  
Linda Denney ◽  
Lorin Maletsky
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Performance Test ◽  
Knee Stability ◽  
Vertical Projection ◽  
Single Plane ◽  
Flexion Extension ◽  
Weight Shift ◽  
Total Knee ◽  
Supporting Base

Stability has been defined as the ability to transfer the vertical projection of the center of gravity to the supporting base and keep the knee as still as possible1. The transfer of weight (load) to a single limb while still in double-stance is functional and simulates every day activities such as loading the dishwasher, transferring laundry, or reaching to pick up an item. Adding rotation in a transverse plane to this weight shift challenges knee stability, especially those with a total knee replacement (TKR). A clinical sign of laxity in mid-flexion indicates a risk for developing symptomatic instability; a common reason for TKR revision2. Laxity is usually measured clinically in a single plane (anterior-posterior) and functionally with added turning maneuvers. Single-leg weight acceptance has been analyzed during athletic activities such as hopping, landing with cutting as well as in the older population with stair ascent and descent3–5. Although single-leg performance tests are a good indicator of knee stability, weight shift during double-stance may be more functional for individuals with a TKR. A functional double-stance test should include both flexion/extension with rotation and loading. Our study utilizes a novel approach (Target Touch Task) in order to facilitate transfer of load to one extremity during squatting or extending while still in double-stance. The objective of this study was to identify strategies utilized by individuals with a TKR while in double-stance transferring load during rotational activities.

Improving the accuracy of tibial component placement during total knee replacement in varus knees with tibial bowing: A prospective randomised controlled study

The Knee ◽  
2019 ◽  
Vol 26 (5) ◽  
pp. 1088-1095 ◽  
Author(s):  
Dhanasekararaja Palanisami ◽  
Chirag Parsana Jagdishbhai ◽  
Mithun Manohar ◽  
Pradeep Ramesh ◽  
Rajkumar Natesan ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Tibial Component ◽  
Controlled Study ◽  
Component Placement ◽  
Randomised Controlled Study ◽  
Total Knee ◽  
Randomised Controlled
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