Torsional characteristics of the Minns meniscal knee prosthesis.

A quasi-static analysis of axial rotation of the femoral component and the torsional forces at different angles of knee flexion was performed on knee preparations. The meniscal knee design had very much lower axial torque against axial rotation characteristics through the whole range of knee flexion than the total condylar design and could be rotated up to 59 degrees in both internal and external rotation before dislocating (i.e., a total axial rotation of 118 degrees). The sliding plateau design had torque-rotation characteristics comparable to those of the total condylar design. Torsional strain was measured on cemented and uncemented preparations, and little difference between the two was observed.