Accuracy of a novel extramedullary femoral alignment guide system in primary total knee arthroplasty

Introduction We aimed to assess the accuracy of a new extramedullary guide system for achieving appropriate femoral component alignment in total knee arthroplasty (TKA) and to determine whether it differed between patients operated on by different surgeons. Materials and methods We performed 100 consecutive primary TKAs in 100 patients using a newly developed extramedullary guide, the “S guide”; 50 were performed by author KM at A Hospital, and 50 by author NM at B Hospital. All patients received the Vanguard RP mobile-bearing prosthesis (Biomet Japan, Tokyo, Japan). We assessed the coronal and sagittal alignment of the femoral component with the mechanical axis using plane radiographs. Data were analyzed statistically using Prism 5.0 software, and a p value of