Analysis of tibial component rotation following total knee arthroplasty using 3D high definition computed tomography.

Malrotation of the tibial component is associated with poor outcomes after total knee arthroplasty, yet the definition and evaluation of this problem remain controversial. Contributing factors to this controversy include inconsistent and cumbersome methods for measuring rotation, based upon transposed measurements from multiple computed tomography images. We developed and tested the reliability of a new, simple method for measuring tibial component rotation based upon a single, three-dimensional high definition, axial computed tomography image. Sixty individual knees after total knee arthroplasty were evaluated. The intra-reliability and inter-reliability both exceeded 0.9 whether the tibial component was made of titanium, cobalt-chrome or all-polyethylene. Based upon these findings we suggest that this technique be used for evaluating tibial component rotation in future studies.