The Effect of Total Hip Arthroplasty Surgical Approach on Postoperative Gait Mechanics Robin M. Queen, PhD,*y Robert J. Butler, PT, PhD, yz Tyler S. Watters, MD,* Scott S. Kelley, MD,* David E. Attarian, MD,* and Michael P. Bolognesi, MD* Abstract: Surgical approach for total hip arthroplasty (THA) is determined by clinician preference from limited prospective data. This study aimed to examine the effect of surgical approach (direct lateral, posterior, and anterolateral) on 6-week postoperative gait mechanics. Thirty-five patients (direct lateral, 8; posterior, 12; anterolateral, 15) were tested preoperatively and 6 weeks after THA. Patients underwent a gait analysis at a self-selected walking speed. A 2-way analysis of variance was used for analysis. Stride length, step length, peak hip extension, and walking speed increased after THA. The 3 surgical approach variables were not significantly different for any of the study variables after THA. All patients showed some increase in selected variables after THA regardless of surgical approach. In this study, surgical approach did not appear to significantly influence the early postoperative gait mechanics that were quantified. Keywords: gait analysis, total hip arthroplasty, surgical approach. © 2011 Elsevier Inc. All rights reserved. An estimated 2.5% of the population older than 40 years receives a total hip arthroplasty (THA) typically as a result of trauma or degenerative joint disease [1]. Patients usually present with reduced pain, improved function, and improved gait after THA surgery. Some common adverse effects and complications after THA include hip dislocation, hip musculature weakness, a Trendelenburg gait pattern, and the presence of a limp during gait [2-6]. It is hypothesized that some of these complications may be associated with the different types of surgical approaches used for THA. A number of studies have assessed gait changes in pa- tients after a THA [7-18]. Typically, after a THA, patients exhibit increased range of motion and improved symme- try of joint motion during gait, whereas changes in gait temporospatial parameters are less consistent [14,17,18]. Cross-sectional studies after the THA surgery have suggested that a posterior (P) surgical approach is most successful in improving hip joint symmetry in compari- son with an anterior and anterolateral (AL) approach; however, the differences in these studies could be attributed to presurgical differences [8,11,19,20]. Studies examining the longitudinal effect of the different surgical approaches for THA on gait mechanics have reported minimal differences between techniques in restoring symmetry in ground reaction forces (GRFs), temporos- patial parameters, or hip torques when factoring in presurgical values [10,12,13]. However, little evidence exists reporting the changes that occur locally at the hip joint during gait when individuals are recovering from different THA surgical approaches. In summary, a number of studies have examined changes in gait after THA; however, there are limited prospective comparisons of hip mechanics during gait between different types of surgical approaches for THA. Therefore, the purpose of this study was to examine changes in gait mechanics between 3 common surgical approaches to the hip (AL, direct lateral [DL], and P) for THA. The changes in gait between the time before surgery and 6 weeks after the surgery were examined. It was expected that all subjects would demonstrate a significant improvement in gait from the preoperative time point to the 6-week postoperative time point and that no significant differences would exist between the surgical approaches. From the *Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina; yMichael W. Krzyzewski Human Performance Lab, Duke University Medical Center, Durham, North Carolina; and zDepartment Community and Family Medicine, Division of Physical Therapy, Duke University Medical Center, Durham, North Carolina. Submitted July 12, 2010; accepted April 21, 2011. The Conflict of Interest statement associated with this article can be found at doi:10.1016/j.arth.2011.04.033. Investigation performed at Duke University Medical Center, Durham, NC. Reprint requests: Robin M. Queen, PhD, Duke Department of Orthopaedic Surgery. Director: Michael W. Krzyzewski Human Performance Lab, 102 Finch Yeager Building, DUMC 3435, Durham, NC 27710. © 2011 Elsevier Inc. All rights reserved. 0883-5403/2606-0013$36.00/0 doi:10.1016/j.arth.2011.04.033 66 The Journal of Arthroplasty Vol. 26 No. 6 Suppl. 1 2011