Intra- and postoperative assessment of femoral component rotation in total knee arthroplasty: an EKA knee expert group clinical review

Purpose Malrotation of the femoral component after primary total knee arthroplasty (TKA) is one of the most important problems leading to painful TKA requiring revision surgery. Methods A comprehensive systematic review of the literature was performed to present current evidence on how to optimally place the femoral component in TKA. Several landmarks and techniques for intraoperative determination of femoral component placement and examination of their reliability were analyzed. Results 2806 articles were identified and 21 met the inclusion criteria. As there is no unquestioned gold standard, numerous approaches are possible which come along with specific advantages and disadvantages. In addition, imaging modalities and measurements regarding postoperative femoral component rotation were also investigated. Femoral component rotation measurements on three-dimensional (3D) reconstructed computerised tomography (CT) images displayed intraclass correlation coefficients (ICC) above 0.85, significantly better than those performed in radiographics or two-dimensional (2D) CT images. Thus, 3D CT images to accurately evaluate the femoral prosthetic component rotation are recommended, especially in unsatisfied patients after TKA. Conclusion The EKA Femoral Rotation Focus Group has not identified a single best reference method to determine femoral component rotation, but surgeons mostly prefer the measured resection technique using at least two landmarks for cross-checking the rotation.

Automated summary

This study reviewed the issue of malrotation of the femoral component after total knee arthroplasty, highlighting the recommendation to use 3D CT images to accurately evaluate the rotation of the femoral prosthetic component, especially in unsatisfied patients. It also found that the measured resection technique using at least two landmarks is preferred by surgeons for determining femoral component rotation.