The mechanical testing of a sliding meniscus knee prosthesis.

A 3-component sliding meniscus knee prosthesis was tested mechanically to evaluate the direct loads and the anteroposterior and mediolateral bending moments on the prosthetic components during the loading phase on a pendulum prosthesis testing machine. The bending moments changed with variation of the component positions. Tilting the tibial plateau produced the greatest change in lateral bending moment on the femoral component but alteration in plateau rotation or femoral tilting produced little change in the low values of the 2 bending moments. It is necessary to ensure that the tibial component is positioned horizontally on the tibial plateau, but it is not necessary to be concerned about the angle of the femoral component to the vertical or the misalignment rotationally of the tibial component. The load ideally passes through the condylar component to the tibia much more centrally than if it were a constrained prosthesis system during the loading range, reducing the likelihood of displacement of the 2 fixed components.