Anterior High-Edge Polyethylene Liner Reduces Dislocation Rates in Dysplastic Hips Following Direct Anterior Approach Hip Arthroplasty

<title>Abstract</title> <p>Purpose To investigate whether anterior positioning of the polyethylene liner high-edge can lower the dislocation rate following direct anterior approach (DAA) total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Method A single-center cohort study was conducted including 269 patients who underwent DAA THA for DDH (Crowe I–III) with secondary osteoarthritis between 2019 and 2023. All procedures used ceramic-on-polyethylene bearing surfaces. The control group (154 hips) received conventional “posterior placement” of the high-edge polyethylene liner (8–12 o’clock position), whereas the experimental group (115 hips) underwent “anterior placement” of the high-edge polyethylene liner (10–2 o’clock position). Postoperative follow-up assessments included radiographic evaluation of implant positioning, complication rates (with a focus on dislocation), Harris Hip Score, and implant survival. Results Postoperative dislocation occurred in 6 patients in the control group (5 anterior dislocations, 1 posterior dislocation). Three anterior dislocations were managed with closed reduction, and the remaining 3 required revision surgery. Only 1 posterior dislocation occurred in the experimental group, which was successfully treated with conservative management. Postoperative infection was noted in 3 patients in the control group and 1 patient in the experimental group, all of whom underwent revision surgery. The dislocation rate was lower in the experimental group than in the control group, though the difference did not reach statistical significance (P &gt; 0.05). No significant differences were observed in acetabular component positioning, Harris Hip Scores, or overall complication rates (P &gt; 0.05). The experimental group demonstrated a higher 6-year postoperative prosthesis survival rate compared with the control group. Conclusion Anterior positioning of the high-edge polyethylene liner during DAA THA for DDH with osteoarthritis may reduce the incidence of postoperative dislocation, particularly anterior dislocation. Further high-quality studies are warranted to validate these findings.</p>