Wear simulation of total knee prostheses using load and kinematics waveforms from stair climbing
Autor: | Saverio Affatato, Sami Abdel-Jaber, Claudio Belvedere, Alberto Leardini |
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Rok vydání: | 2015 |
Předmět: |
Male
Knee Joint Computer science Biomedical Engineering Biophysics Kinematics Prosthesis Design Burnishing (metal) Total knee Activities of Daily Living Materials Testing Waveform Prosthesis design Humans Orthopedics and Sports Medicine Knee Arthroplasty Replacement Knee Simulation Aged business.industry Stair climbing Rehabilitation Structural engineering Middle Aged Healthy Volunteers Biomechanical Phenomena Equipment Failure Analysis Wear simulation Female business Knee Prosthesis human activities |
Zdroj: | Journal of biomechanics. 48(14) |
ISSN: | 1873-2380 |
Popis: | Knee wear simulators are meant to perform load cycles on knee implants under physiological conditions, matching exactly, if possible, those experienced at the replaced joint during daily living activities. Unfortunately, only conditions of low demanding level walking, specified in ISO-14243, are used conventionally during such tests. A recent study has provided a consistent knee kinematic and load data-set measured during stair climbing in patients implanted with a specific modern total knee prosthesis design. In the present study, wear simulation tests were performed for the first time using this data-set on the same prosthesis design. It was hypothesised that more demanding tasks would result in wear rates that differ from those observed in retrievals. Four prostheses for total knee arthroplasty were tested using a displacement-controlled knee wear simulator for two million cycles at 1.1 Hz, under kinematics and load conditions typical of stair climbing. After simulation, the corresponding damage scars on the bearings were qualified and compared with equivalent explanted prostheses. An average mass loss of 20.2±1.5 mg was found. Scanning digital microscopy revealed similar features, though the explant had a greater variety of damage modes, including a high prevalence of adhesive wear damage and burnishing in the overall articulating surface. This study confirmed that the results from wear simulation machines are strongly affected by kinematics and loads applied during simulations. Based on the present results for the full understanding of the current clinical failure of knee implants, a more comprehensive series of conditions are necessary for equivalent simulations in vitro. |
Databáze: | OpenAIRE |
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