Implant Selection and Radiographic and Clinical Outcomes in Patients Receiving Staged Bilateral Total Hip Arthroplasty with Discordant Surgical Approaches.

Introduction: To our knowledge, outcomes of patients undergoing staged, bilateral total hip arthroplasty (THA) via dissimilar surgical approaches have not yet been investigated. This study examined demographics, implant selection, technology utilization, and component positioning between hips in patients who underwent one THA via posterior and one via direct anterior approach and secondarily evaluated patient-reported outcomes.

Methods: There were 36 patients (72 hips) who underwent staged, bilateral, primary, elective THAs via different approaches from January 2012 to December 2023. Patient demographics, intraoperative technology utilization, implants used, and pre- and postoperative Hip Dysfunction and Osteoarthritis Outcome Scores for Joint Replacement (HOOS-JR) scores were recorded. The hip center of rotation, acetabular height and anteversion, and metaphyseal canal fill were measured on postoperative radiographs. Femoral stem coronal and sagittal plane angulation following both approaches were also compared on postoperative radiographs.

Results: There were 15 (41.7%) patients who underwent posterior THA first. The mean time between operations was five years (range, 0.93 to 10.2). Intraoperative technology utilization was more common for the anterior THA (P = 0.002). There were no significant differences in hip center of rotation (P = 0.292), acetabular anteversion (P = 0.428), or acetabular height (P = 0.935) between patients' anterior and posterior approach THAs. The proportion of patients who had posterior stem angulation was significantly greater following anterior THA; neutral stem angulation was seen more frequently following posterior THA (P = 0.005). Lipped liners (P < 0.001), high offset femoral stems (P = 0.007), and dual or triple-taper stems (P < 0.001) were more commonly utilized in posterior THAs. For patients who had pre- and postoperative HOOS-JR for each hip, there was no significant difference in postoperative score improvement between anterior and posterior THAs (P = 0.697), with a mean follow-up time of 2.4 years (range, 0.3 to 9.28) for posterior and 6.1 years (range, 2.8 to 10.3) for anterior THAs (P = 0.249).

Conclusions: Patients undergoing staged, bilateral THAs via different surgical approaches exhibit radiographic characteristics likely attributable to technical challenges for each approach. However, these differences related to approach do not seem to impact short-term clinical and patient-reported outcomes.