Accelerometer-Based Computer Navigation for Performing the Distal Femoral Resection in Total Knee Arthroplasty

The use of intramedullary alignment guides for performing the distal femoral resection in total knee arthroplasty (TKA) have not been shown to be highly accurate. Forty-eight knees underwent a TKA using a portable, accelerometer-based surgical navigation system for performing the distal femoral resection (KneeAlign 2 system; OrthAlign, Inc, Aliso Viejo, Calif). Of the femoral components, 95.8% were placed within 90° ± 2° to the femoral mechanical axis in the coronal plane, and 93.8% of the TKAs had an overall lower extremity alignment within 3° of neutral to the mechanical axis, based on postoperative, standing, hip-to-ankle radiographs. The KneeAlign 2 is highly accurate in positioning the femoral component in TKA, and accelerometer-based navigation is able to reliably determine the hip center of rotation and femoral mechanical axis.