Assessing rotational alignment in total knee arthroplasty.

The authors of this study demonstrate a new method for assessing relative rotational alignment of femoral and tibial components in total knee arthroplasty. This postoperative method requires only a lateral radiograph of the knee in full extension. This technique was demonstrated with repeated measurements by 2 independent observers to be accurate and reproducible in documenting the rotation of knee implants. This technique has clinical application in determining the accuracy of contemporary alignment techniques, assessing the reliability of anatomic landmarks referenced in implant alignment, and documenting the impact of malrotation on the function and longevity of components in total knee arthroplasty.