Do we need intraoperative radiographs for positioning the femoral component in total hip arthroplasty?

Poor long-term results of total hip arthroplasty (THA) can result from femoral component misalignment. There are few reports that discuss the effectiveness of intraoperative radiographs for placing femoral components. This study is a retrospective review to find out the usefulness of intraoperative radiographs in detecting and improving the femoral component misalignment in posterior-approached primary THA. The study group included 150 primary THAs performed between September 2009 and April 2012. After the trial component insertion in lateral decubitus position, intraoperative radiography was performed. The surgeon assessed the femoral component position in three aspects: alignment, leg length, and offset. If it is not following the preoperative template, the surgeon makes the intraoperative adjustments to change the femoral component position. After the operation, postoperative radiograph was taken; the same parameters were measured and were compared to intraoperative findings. The changes in each parameter were classified into three categories: satisfactory, no change, and unsatisfactory. Among the three parameters, if one is satisfactory and the others are not unsatisfactory, we defined it as accurate positioning of the femoral component. Intraoperative adjustments were made in 122 cases (81.3 %). The adjustments included changes in the component size (35.3 %), component alignment (38.6 %), femoral offset (14.0 %), and additional femoral neck cuts (56.0 %). As a result, accurate positioning was successfully achieved in 112 cases (91.8 %) by taking intraoperative radiographs. Our data suggest that intraoperative radiography is a useful method for detecting the errors of placing the femoral components, and the success of a surgeon to correct those errors after detecting them intraoperatively.