Journal Published Online: 05 December 2014
Volume 44, Issue 1

Assessment of Physiological Load Testing of Total Knee Implants



As the demands for total knee arthroplasty continue to rise, the methodologies for testing current and future devices may require refinement. Current standards have not been shown to simulate wear rates and patterns seen in explanation studies. The purpose of this study was to assess a combination of potentially more physiological testing protocols. Four identical TKAs were implanted into four fresh cadaver knees and tested in a knee simulator. Each knee was tested using the ISO load control testing standard (ISO 14243-1) and five novel testing protocols representing different activities of daily living. Motions were recorded between the tibia and femur (tibial rotation, anterior–posterior (AP) motion) and between the implant and bone (superior-inferior femoral condylar motion, tibial tray vertical motion). The total tibial AP cadaver motion varied from a total of 6.2 to 7.6 mm for the six loading protocols during a cycle of motion. For the ISO gait profile and the new gait, stair ascent and stair descent profiles, the range of tibial cadaver rotation varied from 9.2° with the ISO gait to 10.2° with the stair ascent. The crossover turn had a range of 16.3° and the pivot turn a range of 18.7°. Larger tibial tray AP motion, relative to the tibia, occurred with the pivot turn and crossover turn motions, compared to the gait motions or stair activities. This study supports the viability of new and alternative loading profiles. We suggest that these novel profiles should be considered by the ASTM or ISO as they seek to supplement or replace the profiles currently in use.

Author Information

Van Valkenburg, Scott
SUNY Upstate Medical Univ., Syracuse, NY, US
Werner, Frederick
SUNY Upstate Medical Univ., Syracuse, NY, US
Bhimji, Safia
Stryker Orthopaedics, Mahwah, NJ, US
White, Bruce
AMTI Inc., Watertown, MA, US
Asseman, François
AMTI Inc., Watertown, MA, US
Pages: 10
Price: $25.00
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Stock #: JTE20140015
ISSN: 0090-3973
DOI: 10.1520/JTE20140015