Using a surrogate contact pair to evaluate polyethylene wear in prosthetic knee joints

2015 ◽  
Vol 104 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Anthony P. Sanders ◽  
Carly A. Lockard ◽  
Joel N. Weisenburger ◽  
Hani Haider ◽  
Bart Raeymaekers
Keyword(s):  
Polyethylene Wear ◽  
Knee Joints ◽  
Contact Pair ◽  
Prosthetic Knee

A New Modeling Method to Characterize the Stance Control Function of Prosthetic Knee Joints

2019 ◽  
Vol 66 (4) ◽  
pp. 1184-1192 ◽  
Author(s):  
Jan Andrysek ◽  
Jessica Tomasi ◽  
Matthew Leineweber ◽  
Arezoo Eshraghi
Keyword(s):  
Control Function ◽  
Modeling Method ◽  
Knee Joints ◽  
Prosthetic Knee ◽  
Stance Control

Mobility and Stability of the Intact and Replaced Knee

2015 ◽  
Author(s):  
John Goodfellow ◽  
John O'Connor ◽  
Hemant Pandit ◽  
Christopher Dodd ◽  
David Murray
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Final Section ◽  
Sagittal Plane ◽  
Polyethylene Wear ◽  
Mobile Bearing ◽  
Theoretical Background ◽  
Cruciate Retaining ◽  
Prosthetic Knee ◽  
Total Knee

Having demonstrated in Chapter 2 that a fully conforming mobile bearing can minimise polyethylene wear, in this chapter we show that a mobile bearing prosthesis, unconstrained in the sagittal plane, can restore natural mobility and stability. For surgeon readers who are less interested in the theoretical background, it might be advisable to go straight to Chapter 4, Indications, or to start by reading the final section of this chapter, The Loaded Prosthetic Knee. If that proves interesting, the surgeon might attempt The Unloaded Prosthetic Knee. For the more research minded surgeon or engineer, it seems more logical to start with the Unloaded Natural Knee (the longest section of the chapter) and to read from there. The chapter may also be of interest to those surgeons embarking on the use of a bi-cruciate retaining total knee replacement.

Evaluation and Analysis of Different Types of Prosthetic Knee Joint Used by above Knee Amputee

2020 ◽  
Vol 398 ◽  
pp. 34-40 ◽  
Author(s):  
Fahad Mohanad Kadhim ◽  
Jumaa Salman Chiad ◽  
Maryam Abdul Salam Enad
Keyword(s):  
Gait Cycle ◽  
Reaction Force ◽  
Maximum Velocity ◽  
Knee Joints ◽  
Von Mises Stress ◽  
Prosthetic Knee ◽  
Prosthetic Limb ◽  
Left And Right ◽  
The Difference ◽  
Von Mises

Four prosthetic knee joints (polycentric knee weight activating-4bar and friction, extension assist controlled),(single axis knee weight activating and friction, internal extension assist controlled), (single axis knee weight activating-4bar and hydraulically, controlled) and (polycentric knee geometric locking-6bar, hydraulically controlled) for a trans-femoral patient were tested. The tests were conducted to find the maximum velocity as well as discussing the most comfortable prosthetic forthe patient and walking stability for these prosthetic knees by examining the gait cycle and measuring the ground reaction force (GRF), using force a plate device. Also, the interface pressure was measured between socket and stump muscles by using F-socket device to get the stress distribution during walking with a prosthetic knee. Results manifested that the polycentric knee geometric locking - 6bar, hydraulically controlled is the best because of the good homogenous distribution of GRF between the healthy and prosthetic limb, during which the difference between both the healthy and prosthetic limb is with the least value (4%).And, K4 gives the minimum value of differences in contact pressure between the left and right limb with a value of (24%), it alsoimparts the maximum symmetry between the left and right limb according to the gait cycle parameters.The best results of the interface pressures and kinovea velocity are achieved whenK4 is used with (132.4KPa, 0.71m/s), respectively. Finally, the polycentric knee geometric locking - 6bar, hydraulically controlled is the best according to the ANSYS results during which it yields the minimum values of Von-Mises stress with 14.24MPa and a maximum factor of safety of 3.11.

Biomechanical responses of young adults with unilateral transfemoral amputation using two types of mechanical stance control prosthetic knee joints

2020 ◽  
Vol 44 (5) ◽  
pp. 314-322
Author(s):  
Jan Andrysek ◽  
Daniela García ◽  
Claudio Rozbaczylo ◽  
Carlos Alvarez-Mitchell ◽  
Rebeca Valdebenito ◽  
...  
Keyword(s):  
Young Adults ◽  
Knee Joint ◽  
Stance Phase ◽  
Pelvic Tilt ◽  
Swing Phase ◽  
Knee Joints ◽  
Transfemoral Amputation ◽  
Phase Duration ◽  
Prosthetic Knee ◽  
Stance Control

Background: Prosthetic knee joint function is important in the rehabilitation of individuals with transfemoral amputation. Objectives: The objective of this study was to assess the gait patterns associated with two types of mechanical stance control prosthetic knee joints—weight-activated braking knee and automatic stance-phase lock knee. It was hypothesized that biomechanical differences exist between the two knee types, including a prolonged swing-phase duration and exaggerated pelvic movements for the weight-activated braking knee during gait. Study design: Prospective crossover study. Methods: Spatiotemporal, kinematic, and kinetic parameters were obtained via instrumented gait analysis for 10 young adults with a unilateral transfemoral amputation. Discrete gait parameters were extracted based on their magnitudes and timing. Results: A 1.01% ± 1.14% longer swing-phase was found for the weight-activated braking knee (p < 0.05). The prosthetic ankle push-off also occurred earlier in the gait cycle for the weight-activated braking knee. Anterior pelvic tilt was 3.3 ± 3.0 degrees greater for the weight-activated braking knee. This range of motion was also higher (p < 0.05) and associated with greater hip flexion angles. Conclusions: Stance control affects biomechanics primarily in the early and late stance associated with prosthetic limb loading and unloading. The prolonged swing-phase time for the weight-activated braking knee may be associated with the need for knee unloading to initiate knee flexion during gait. The differences in pelvic tilt may be related to knee stability and possibly the different knee joint stance control mechanisms. Clinical relevance Understanding the influence of knee function on gait biomechanics is important in selecting and improving treatments and outcomes for individuals with lower-limb amputations. Weight-activated knee joints may result in undesired gait deviations associated with stability in early stance-phase, and swing-phase initiation in the late stance-phase of gait.

An Architecture for Direct Measurement of Transfemoral Prosthesis Gait Beyond the Gait Laboratory Setting

2014 ◽  
Author(s):  
Jonathan A. Gacioch ◽  
Kevin B. Fite ◽  
Adam K. Arabian ◽  
Toshiki Kobayashi ◽  
David A. Boone ◽  
...  
Keyword(s):  
Knee Kinematics ◽  
Knee Joints ◽  
Single Subject ◽  
Laboratory Setting ◽  
Transfemoral Amputation ◽  
Kinetic Measurements ◽  
Prosthetic Knee ◽  
Rapid Acquisition ◽  
Composite Energy ◽  
Transfemoral Prosthesis

The work presented here details the development of a wireless instrumentation architecture for direct gait measurement in a transfemoral prosthesis. The system comprises a pair of multi-axis load cells located proximal to the ankle and knee joints of the prosthesis that provide a measure of moments and axial force above and below the prosthetic knee. The kinetic measurements are supplemented with knee kinematics measured using a modular goniometer attached lateral to the prosthetic knee and ground contact as indicated with a pneumatic sensor at the prosthetic heel. Each instrument wirelessly transmits collected data to host PCs, enabling direct gait measurements free of the constraints of a conventional gait laboratory setting. The data acquisition system was evaluated with a single subject with unilateral transfemoral amputation walking with a polycentric knee, composite energy-return foot, and daily-use socket. Experimental results were collected for the subject walking through a theater, enabling the rapid acquisition of gait data for level-ground walking and incline ascent/descent without the need for a motion-capture camera array or floor-embedded force plates.

A comparative evaluation of the Adaptive® knee and Catech® knee joints: A preliminary study

2008 ◽  
Vol 32 (1) ◽  
pp. 84-92 ◽  
Author(s):  
F. Jepson ◽  
D. Datta ◽  
I. Harris ◽  
B. Heller ◽  
J. Howitt ◽  
...  
Keyword(s):  
Knee Joint ◽  
Knee Joints ◽  
Hydraulic Control ◽  
Cost Index ◽  
Pneumatic Control ◽  
Prosthetic Knee ◽  
Physiological Cost ◽  
Hybrid Controller ◽  
Preliminary Study ◽  
Force Time

The Adaptive® knee joint is a microprocessor-controlled prosthetic knee that incorporates both pneumatic and hydraulic control in one electronic unit. Pneumatic control is said to provide control during swing phase and the hydraulic control during the stance phase of the gait. This hybrid controller is triggered by a computer contained within the knee that responds to input from force, time and angle sensors. The microprocessor then selects an appropriate speed and stability setting. The Catech® knee joint is a conventional hydraulic knee joint. The aim of this study was to compare the Adaptive® and Catech® knee joints in established trans-femoral amputees. The patients meeting the inclusion criteria were all established trans-femoral amputees using the Catech® knee joint. The study was carried out by performing gait analysis, assessing energy requirements using the Physiological Cost Index (PCI) and using questionnaires. There was no significant benefit gained from the use of the Adaptive® knee over the Catech® knee joint in our small study group.

scholarly journals Gambaran Proses Pembuatan Transfemoral Prosthesis Menggunakan Polycentric Knee Joint Untuk Pasien Amputasi Atas Lutut

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Ismi Dwi Syafitri ◽  
Nur Rachmat
Keyword(s):  
Knee Joint ◽  
Lower Limbs ◽  
World Health ◽  
Knee Joints ◽  
Transfemoral Amputation ◽  
Prosthetic Knee ◽  
Gait Abnormality ◽  
Gait Abnormalities ◽  
Health Organization ◽  
Transfemoral Prosthesis

Abstract : Transfemoral Amputasi, Transfemoral Prosthesis, Polycentric Knee Joint. World Health Organization (WHO) estimated that there are 40 million amputees throughout the developing countries. Amputation in the lower limbs reached 85% -90% of all amputations. Transfemoral amputation because of this amputation occurs in the thigh that passed through the femur bone. Amputation causes significant gait abnormalities. amputation levels increased, the functional level is reduced, and the characteristic of the gait abnormality is immediately apparent. Transfemoral Prosthesis is artificial limb that made for above knee amputation. making process of transfemoral prosthesis includes assessment, measurement, casting, fabrication, fitting, finishing. Of all components for transfemoral patients, prosthetic knee joints are the most important components that can affect to gait stability. The choice for the type of popular passive knee mechanism is polycentric knee. The polycentric knee joint mechanism, linkage of 4 and 6 bar mechanisms have been used to increase stability during the stance and kinematic phase of the swing phase.

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