Rotational Alignment of the Femoral Component in Computer-Assisted Total Knee Arthroplasty

• Main Authors: Mark Clatworthy, MD, Kimberly Lindberg, MD, Walter Wray III, MD, Christi Sychterz Terefenko, MS, Douglas Dennis, MD, David Pollock, MD
• Format: Article
• Language: English
• Published: Joint Implant Surgery & Research Foundation 2012-08-01
• Series: Reconstructive Review
• Online Access: https://reconstructivereview.org/ojs/index.php/rr/article/view/14
• ISSN: 2331-2262; 2331-2270

This study compared two Computer Assisted Surgery (CAS) methods in 212 total knee arthroplasties to evaluate the differences between  anatomic landmark axes in determining rotational position of the femoral component. Overall, there were large variations between CAS defined component orientation using an optimized gap-balancing technique and component orientation using anatomic reference axes (range, 16º internal rotation to 16º external rotation). If based on anatomic landmarks, these large variations would have led to asymmetrical flexion gaps in up to 60% of the knees studied. Of the anatomic axes studied, the posterior condylar axis was the only axis not significantly different from CAS optimized orientation. If anatomic landmarks are used for femoral component rotation with either a conventional or a CAS technique, asymmetric trapezoidal flexion gaps may result. Key Words: total knee arthroplasty, balancing, component rotation, Computer Assisted Surgery