Volume 9, Issue 1 (January 2012)

    Mobility and Contact Mechanics of a Rotating Platform Total Knee Replacement

    (Received 9 August 2011; accepted 11 August 2011)

    Published Online: 2011


      Format Pages Price  
    PDF 13 $25   ADD TO CART


    Despite their increasing clinical usage, mobile-bearing total knee replacements have not been well characterized biomechanically. An experimental and finite element analysis was done to asses the mobility and contact mechanics of a widely used rotating platform total knee replacement. Parameters that varied were axial load, condylar load allocation, flexion angle, and static versus dynamic loading. Similar results from the physical model and finite element model lend credence to the validity of the findings. The torque required to initiate rotation (static torque) was greater than that to sustain rotation (dynamic torque). At four times body weight axial load, peak resisting torque measured was 9.47 ± 0.61 and 5.51 ± 0.38 N-m, for static and dynamic torque, respectively. A 60–40 condylar load allocation produced slightly less resisting torque than the 50-50 load. For all practical purposes, the polyethylene insert rotated simultaneously with the femoral component, leading to maintenance of high contact area, desirable behavior clinically. Walking cycle simulations produced a total axial rotation range of motion of 6°. The high frictional torques observed at the mobile interface may explain why a percentage of these mobile-bearings fail to rotate under routine functional load.

    Author Information:

    Otto, Jason K.
    Univ. of Iowa,

    Callaghan, John J.
    Univ. of Iowa,

    Brown, Thomas D.
    Univ. of Iowa,

    Stock #: JAI104266

    ISSN: 1546-962X

    DOI: 10.1520/JAI104266

    ASTM International is a member of CrossRef.

    Title Mobility and Contact Mechanics of a Rotating Platform Total Knee Replacement
    Symposium , 0000-00-00
    Committee F04