Ikawa T, et al. – This research was designed to assess the impacts of using a portable, accelerometer–based surgical navigation system (KneeAlign2) in total knee arthroplasty (TKA) on the alignment of the femoral component, and blood loss. Findings demonstrated that the KneeAlign2 system offered a technically straightforward method for detecting the femoral head and performing an accurate distal femoral resection at TKA with markedly less blood loss than with a conventional intramedullary guide.