Robotic arm-assisted total hip arthroplasty in patients with hip dysplasia: a systematic review

This review summarizes radiographic, clinical and patient reported outcomes following robotic-arm assisted total hip arthroplasty (RAA-THA) in patients with developmental dysplasia of the hip (DDH), with comparisons to conventional (C-THA) and navigation (N-THA) techniques. MEDLINE, EMBASE and CENTRAL databases were searched for studies on DDH patients undergoing RAA-THA. Outcomes assessed included radiographic accuracy, patient-reported outcome-measures (PROMs), intraoperative outcomes, and complications. Eleven studies were included, analyzing 1150 hips (641 RAA-THA, 383 C-THA, 126 N-THA) with a median patient age of 60.5 years, and median BMI of 24.6. DDH severity was distributed as 59.6% Crowe I, 25.3% Crowe II/III hips, and 15.1% Crowe IV hips. Comparative studies among Crowe I-III hips showed significantly lower errors in cup inclination and anteversion with RAA-THA compared to both C-THA and N-THA. RAA-THA also achieved greater accuracy in restoring the center of rotation for Crowe I-III, but no difference was observed in Crowe IV hips. No significant differences were found in short-term PROMs, and intraoperative outcomes and complication rates were comparable between groups. RAA-THA may improve cup placement accuracy in Crowe I-III hips compared to C-THA and N-THA. However, the accuracy of Crowe IV hips remains unclear, with limited evidence available. Furthermore, radiographic benefits did not translate into significant differences in short-term PROMs, intraoperative outcomes, or complication rates. Future studies should include larger cohorts of patients with severe dysplasia and provide longer follow-up to better evaluate the efficacy and implant survivorship of RAA-THA in these complex cases. Level of Evidence: IV.