Assessing rotational alignment in total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Accurate component alignment is crucial for total knee arthroplasty (TKA) success.
• Rotational alignment, particularly of the femoral and tibial components, is challenging to assess postoperatively.
• Existing methods for evaluating rotational alignment may be complex or invasive.

Purpose of the Study:

• To present and validate a novel, straightforward radiographic method for assessing the relative rotational alignment of femoral and tibial components after TKA.
• To establish the accuracy and reproducibility of this new technique using independent observers.

Main Methods:

• A new method utilizing a single lateral knee radiograph in full extension was developed.
• Two independent observers performed repeated measurements to assess the technique's reliability.
• The technique focuses on documenting the rotational position of knee implants.

Main Results:

• The developed radiographic technique was demonstrated to be accurate in assessing component rotation.
• Repeated measurements by independent observers confirmed the reproducibility of the technique.
• The method reliably documents the rotational alignment of knee implants.

Conclusions:

• This new lateral radiograph technique provides an accurate and reproducible means for postoperative assessment of rotational alignment in TKA.
• The method has significant clinical utility for evaluating current alignment techniques and implant landmark reliability.
• It can also be used to investigate the effects of malrotation on TKA component function and longevity.