Difference in Stem Alignment Between the Direct Anterior Approach and the Posterolateral Approach in Total Hip Arthroplasty

The purpose of this study was to investigate the effects of different surgical approaches, the posterolateral approach (PLA) and the direct anterior approach (DAA), on postoperative femoral anteversion and stem coronal and sagittal alignment in total hip arthroplasty (THA), and to identify the factors related to postoperative femoral anteversion and stem alignment. A total of 209 hips of 181 patients were evaluated. THA was performed through the PLA in 80 hips and through the DAA in 129 hips. Femoral anteversion and stem alignment were measured on postoperative computed tomography images. The factor related to postoperative anteversion change was preoperative femoral anteversion, and the surgical approaches did not affect the postoperative anteversion change, while surgical approach did have an effect on stem sagittal alignment.